Statistics
BAMF
statistics_test.docx1 Suppose that the average song length in America is 4 minutes with a standard deviation of 1.25 minutes. It is known that song length is not normally distributed. Find the probability that a single randomly selected song from the population will be longer than 4.25 minutes. Round to the nearest thousandth.
Answer
A. 0.579
B. 0.079
C. 0.421
D. This probability cannot be determined because we do not know the distribution of the population.
2 An outcome of an experiment or study that is large enough to have a real effect on people’s health or lifestyle is said to have clinical significance.
Answer
True
False
3 Are average SAT scores higher in schools where a smaller percentage of graduating students take the test? To answer this question 10 schools are sampled and the average SAT and percentage of students taking the test were recorded. 2002 SAT results of regional high schools were sampled and the data is given below. Use that data to test if there is a relation between the proportion of seniors that take the test and the average SAT scores. At 95% confidence level.
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2002 SAT results of a sample of Western North Carolina High Schools. |
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Mean SAT scores |
1106 |
1040 |
1013 |
1066 |
1061 |
1075 |
1058 |
997 |
1014 |
965 |
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Percent tested |
61 |
59 |
44 |
54 |
72 |
74 |
80 |
32 |
49 |
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What is R2 for the equation?
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A. R2=0.793 |
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B.B. R2= 0.429 |
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C. C. R2=0.326 D. D. R2=0.357
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4. Suppose the Acme Drug Company develops a new drug, designed to prevent colds. The company states that the drug is equally effective for men and women. To test this claim, they choose a simple random sample of 100 women and 200 men from a population of 100,000 volunteers. At the end of the study, 38% of the women caught a cold; and 51% of the men caught a cold. State the null and alternative hypothesis:
Answer
A. H0: p1 = p2 : HA: p1 = p2 :
B. H0: p1 < p2 HA: p1< p2 :
C. H0: p1 > p2 HA: p1> p2 :
D. H0: p1 ≠ p2 HA: p1= p2 :
5 An insurance company is reviewing its current policy rates. When originally setting the rates they believed that the average claim amount was $1,800. They are concerned that the true mean is actually higher than this, because they could potentially lose a lot of money. They randomly select 40 claims, and calculate a sample mean of $1,950. Assuming that the standard deviation of claims is $500, and set α = 0.05, test to see if the insurance company should be concerned. What do we interpret from the problem?
Answer
A. P value < α so we reject Ho
B. P value > α so we do not reject Ho
C. P value < α so we do not reject Ho
D. P value < α so we reject Ho
6 1. To achieve a significance level of α, if the p-value is less than (or equal to) α, then________________
Answer
A. accept the null hypothesis
B. do not reject the null hypothesis
C. reject the null hypothesis
D. accept the alternative hypothesis
7 1. Neuroscience researchers examined the impact of environment on rat development. Rats were randomly assigned to be raised in one of the four following test conditions: Impoverished (wire mesh cage - housed alone), standard (cage with other rats), enriched (cage with other rats and toys), super enriched (cage with rats and toys changes on a periodic basis). After two months, the rats were tested on a variety of learning measures (including the number of trials to learn a maze to a three perfect trial criteria), and several neurological measure (overall cortical weight, degree of dendritic branching, etc.). The data for the maze task is below. Compute the appropriate test for the data provided below. Compute the appropriate test using α=0.01.
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Impoverished |
Standard |
Enriched |
Super Enriched |
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22 |
17 |
12 |
8 |
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19 |
21 |
14 |
7 |
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15 |
15 |
11 |
10 |
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24 |
12 |
9 |
9 |
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18 |
19 |
15 |
12 |
Ho: Environment will have no impact on learning ability as operationalized by maze performance in rats.
Ha: Environment will have an impact on learning ability as operationalized by maze performance in rats.
Which statement is false?
Answer
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A. There is no significant difference between the impoverished group and the standard group (Fcomp = 2.32 and qobs= 2.15, n.s.) |
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B. There is a significant difference between the impoverished group and both the enriched and supenriched group (Fcomp = 16.15 and qobs= 5.68, p < .01) and Fcomp = 31.90 and qobs= 7.98, p < .01), respectively) |
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C. There is not a significant difference between the standard group and the supenriched group (Fcomp = 17.03 and qobs= 5.83, p < .05). |
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D. There is no significant difference between the enriched group and the superenriched group (Fcomp = 2.65 and qobs= 2.30, p < .05))
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8. ANOVA tests whether a categorical variable is associated with a numerical variable. This is the same as testing whether the mean value of a numerical variable is different in different groups.
Answer
True
False
9 In order to compare proportions from two populations, we write the null hypothesis as
Answer 1.H0: p1 < p2
B. H0: p1 > p2
C. H0: p1 ≠ p2
D. H0: p1 = p2
10 Suppose the Acme Drug Company develops a new drug, designed to prevent colds. The company states that the drug is equally effective for men and women. To test this claim, they choose a simple random sample of 100 women and 200 men from a population of 100,000 volunteers. At the end of the study, 38% of the women caught a cold; and 51% of the men caught a cold. What is the z value for problem?
Answer
A. 1.96
B. -2.13
C. 2.20
D. -1.50
11 An insurance company is reviewing its current policy rates. When originally setting the rates they believed that the average claim amount was $1,800. They are concerned that the true mean is actually higher than this, because they could potentially lose a lot of money. They randomly select 40 claims, and calculate a sample mean of $1,950. Assuming that the standard deviation of claims is $500, and set α = 0.05, test to see if the insurance company should be concerned. State the null and alternative hypothesis:
Answer
A. Ho =1800, Ha≠1800
B. Ho ≥800, Ha<1800
C. Ho >1800, Ha<1800
D. Ho ≤1800, Ha>1800
12 Neuroscience researchers examined the impact of environment on rat development. Rats were randomly assigned to be raised in one of the four following test conditions: Impoverished (wire mesh cage - housed alone), standard (cage with other rats), enriched (cage with other rats and toys), super enriched (cage with rats and toys changes on a periodic basis). After two months, the rats were tested on a variety of learning measures (including the number of trials to learn a maze to a three perfect trial criteria), and several neurological measure (overall cortical weight, degree of dendritic branching, etc.). The data for the maze task is below. Compute the appropriate test for the data provided below. Compute the appropriate test using α=0.01.
|
Impoverished |
Standard |
Enriched |
Super Enriched |
|
22 |
17 |
12 |
8 |
|
19 |
21 |
14 |
7 |
|
15 |
15 |
11 |
10 |
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24 |
12 |
9 |
9 |
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18 |
19 |
15 |
12 |
Ho: Environment will have no impact on learning ability as operationalized by maze performance in rats.
Ha: Environment will have an impact on learning ability as operationalized by maze performance in rats.
What is your F value and Fcrit?
Answer
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A. 135.6, 107.8 |
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B. 11.71, 5.65 |
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C. 10.01, 3.65 |
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D. 12.72, 5.29 |
13 An insurance company is reviewing its current policy rates. When originally setting the rates they believed that the average claim amount was $1,800. They are concerned that the true mean is actually higher than this, because they could potentially lose a lot of money. They randomly select 40 claims, and calculate a sample mean of $1,950. Assuming that the standard deviation of claims is $500, and set α = 0.05, test to see if the insurance company should be concerned. What is the p value associated with test statistic?
Answer 1.
A. 0.05
B. 0.067
C. 0.07
D. 0.045
14 . Use the following information to answer the question. A statistics professor is interested in learning whether there is a positive association between number of posts by online students on a message board and the final class average in an online statistics course. The computer output below shows the results from a regression model in which the final class average was predicted by the number of message board posts. Assume that the conditions of the linear regression model are satisfied.
Choose the correct observed value of the test statistic and the p-value. Round to the nearest thousandth.
Answer
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A. t = 0.002, p = 3.707 |
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B. t = 0.777, p = 0.002 |
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C. t = 3.708, p = 0.005 |
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D. t = 3.708, p = 0.002 |
15 The effectiveness of advertising for two rival products (Brand X and Brand Y) was compared. Market research at a local shopping center was carried out, with the participants being shown adverts for two rival brands of coffee, which they then rated on the overall likelihood of them buying the product (out of 10, with 10 being "definitely going to buy the product"). Half of the participants gave ratings for one of the products, the other half gave ratings for the other product. Is there a significant difference between Brand X and Brand Y at the α=0.05 level.
Brand X Brand Y Participant Rating Participant Rating
What is T1 and T2?
Answer
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A. |
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. T1=42, T2=67 |
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B. |
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B. T1=32, T2=26 |
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C. |
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C. T1=23, T2=55 |
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D. |
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D. T1=45, T2=67 |
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16 An economist conducted a hypothesis test to test the claim that the average cost of eating a meal at home increased from 2009 to 2010. The average cost of eating a meal at home in 2009 was $5.25 per person per meal. Assume that all conditions for testing have been met. He used technology to complete the hypothesis test. Following is his null and alternative hypothesis and the output from his graphing calculator.
Ho: μ = $5.25
Ha: μ > $5.25
At the 5% significance level, choose the statement that contains the correct conclusion regarding the hypothesis and the original claim.
Answer
A. Reject the null hypothesis; there is not sufficient evidence to support the claim that the average cost of eating at home has increased since 2009.
B. Reject the null hypothesis; there is sufficient evidence to support the claim that the average cost of eating at home has increased since 2009.
C. Fail to reject the null hypothesis; there is not sufficient evidence to support the claim that the average cost of eating at home has increased since 2009.
D. Fail to reject the null hypothesis; there is sufficient evidence to support the claim that the average cost of eating at home has increased since 2009.
17 The Webster University librarian believes that more than 60% of the books checked out by students was fictional material. In a random sample of 1000 students who checked books out in the last year, 628 checked out fictional material. Hypothesis level of significance is 0.05. What conclusion do we make from result?
Answer
A. p-value is greater than 5%, reject Ho.
B. p-value is less than 5%, accept Ho.
C. p-value is less than 5%, reject Ho.
D. Not sufficient information to reject or accept null hypothesis
18 Are average SAT scores higher in schools where a smaller percentage of graduating students take the test? To answer this question 10 schools are sampled and the average SAT and percentage of students taking the test were recorded. 2002 SAT results of regional high schools were sampled and the data is given below. Use that data to test if there is a relation between the proportion of seniors that take the test and the average SAT scores. At 95% confidence level.
|
2002 SAT results of a sample of Western North Carolina High Schools. |
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|
Mean SAT scores |
1106 |
1040 |
1013 |
1066 |
1061 |
1075 |
1058 |
997 |
1014 |
965 |
|
Percent tested |
61 |
59 |
44 |
54 |
72 |
74 |
80 |
32 |
49 |
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What is the equation of the line?
Answer
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A. SAT Score = 3.86*(% Tested) + 400.39 |
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B. SAT Score = 1.86*(% Tested) + 44.85 |
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C. SAT Score = 2.98*(% Tested) + 932.69 D |
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SAT Score = 1.86*(% Tested) + 932.69 |
19
Use the following information to answer the question. A statistics professor is interested in learning whether there is a positive association between number of posts by online students on a message board and the final class average in an online statistics course. The computer output below shows the results from a regression model in which the final class average was predicted by the number of message board posts. Assume that the conditions of the linear regression model are satisfied.
Choose the correct decision regarding the null hypothesis and the correct conclusion. State your conclusion using a significance level of 5%.
Answer
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A. Fail to reject Ho. There is not enough evidence to conclude that the final class average is positively associated with the number of message board posts.
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B. Fail to reject Ho. There is enough evidence to conclude that the final class average is positively associated with the number of message board posts. |
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C. Reject Ho. There is not enough evidence to conclude that the final class average is positively associated with the number of message board posts.
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D. Reject Ho. There is enough evidence to conclude that the final class average is positively associated with the number of message board posts |
20 The t-distribution’s shape depends on only one parameter, called the
Answer
A. mean
B. standard deviation
C. degrees of freedom
D. all of the above
21 Which of the following is the statistic that compares the variation between groups to the variation within groups?
Answer
A. z-statistic
B. F-statistic
C. t-statistic
D. P-value
22 The Webster University librarian believes that more than 60% of the books checked out by students was fictional material. In a random sample of 1000 students who checked books out in the last year, 628 checked out fictional material. Hypothesis level of significance is 0.05. What is the test statistic?
Answer
A. 1.81
B. 1.96
C. 2.0
D. 1.76
23 A research study was conducted to examine the clinical efficacy of a new antidepressant. Depressed patients were randomly assigned to one of three groups: a placebo group, a group that received a low dose of the drug, and a group that received a moderate dose of the drug. After four weeks of treatment, the patients completed the Beck Depression Inventory. The higher the score, the more depressed the patient. The data are presented below. Compute the appropriate test using α=0.01.
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Placebo |
Low Dose |
Moderate Dose |
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38 |
22 |
14 |
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47 |
19 |
26 |
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39 |
8 |
11 |
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25 |
23 |
18 |
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42 |
31 |
5 |
Ho: There will be no difference in depression levels between the three groups.
Ha: There will be a difference somewhere in depression levels between the three levels of drug groups
Is there a significant difference between the groups?
Answer
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A. No there is no significant difference groups |
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B. Yes there is a significant difference between the groups |
24Pre-school Attendance and Pre-algebra Achievement (these are contrived data, based on a real study) In these times of educational reform, attention has been focused on pre-school for all children. Since many districts are facing budget cuts, funding pre-school programs may impact other offerings. Before making their recommendations, administrators in a large urban district take a random sample of 50 seventh graders and compare the pre-algebra achievement levels of those who attended pre-school and those who did not. If achievement is independent of attending pre-school then the proportions at each level should be equal. Use the counts in the frequency table to determine if there is an association between attending pre-school and pre-algebra achievement.
Ho: Pre-algebra achievement is independent of pre-school attendance. Ha: There is a relationship between Pre-algebra achievement and pre-school attendance
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Below grade level |
At grade Level |
Advanced |
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Pre-school |
8 (5.6) |
6 (8.4) |
6 (6) |
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No Pre-school |
6 (8.4) |
15 (12.6) |
9 (9) |
Answer
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a. A. Chi-squared = 14.35 with p-value = .250 , do not reject Ho |
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B. B. Chi-squared = 2.85 with p-value = .239, do not reject Ho |
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C. C. Chi-squared = 4.25 with p-value = .034 , reject Ho |
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D. Chi-squared = 1.47 with p-value = .0.620, do not reject Ho |
25 10. The Webster University librarian believes that more than 60% of the books checked out by students was fictional material. In a random sample of 1000 students who checked books out in the last year, 628 checked out fictional material. Hypothesis level of significance is 0.05. What is p value for test statistic?
Answer
A. 0.045
B. 0.060
C. 0.052
D. 0.035
26 Formulating questions which will encompass all possible responses is an important process in obtaining statistical polling data.
Answer
True
False
27 The sample mean is
Answer
A. the arithmetic average of a sample of data
B. an estimate of a population mean
C. unbiased, if the sample is a random sample
D. all of the above
28 The effectiveness of advertising for two rival products (Brand X and Brand Y) was compared. Market research at a local shopping center was carried out, with the participants being shown adverts for two rival brands of coffee, which they then rated on the overall likelihood of them buying the product (out of 10, with 10 being "definitely going to buy the product"). Half of the participants gave ratings for one of the products, the other half gave ratings for the other product. Is there a significant difference between Brand X and Brand Y at the α=0.05 level.
Brand X Brand Y Participant Rating Participant Rating
1. Is there a difference in the ratings between the brands? Which is better rated?
A. No, neither
B. Yes, Brand X
C. Yes, Brand Y
D. Yes, Brand Z
29 For all populations, the sample mean is unbiased when estimating the population mean.
True
False
30 A researcher wanted to know if there was a difference in the percentage of cartoons that men and woman consider funny. α=0.05. He accumulated the following data. Women: 84, 97, 58, 90,
Men: 88, 90, 52, 97, 86,
What is the null hypothesis and alternative hypothesis?
Answer
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A. Ho µ1≤ µ2 Ha µ1> µ2 |
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B. Ho: µ1= µ2 Ha µ1≠ µ2 |
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C. Ho: µ1≥ µ2 Ha µ1< µ2 |
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D. Ho µ1≠ µ2 Ha µ1= µ2 |
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31 |
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31 Researchers use random assignment to ensure that different treatment groups are as different as possible, so that the only real difference between groups is the treatment they receive.
True False
32 Use the following information to answer the question. A random sample of 30 married couples were asked to report the height of their spouse and the height of their biological parent of the same gender as their spouse. The output of a regression analysis for predicting spouse height from parent height is shown. Assume that the conditions of the linear regression model are satisfied.
What is the slope of the regression line? Choose the statement that is the correct interpretation of the slope in context.
Answer
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A. The slope is 48.40. On average, for each inch taller a parent is, the spouse is about 48.40 inches taller, in the sample. |
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B. The slope is 0.25. On average, for each 0.25 inches taller a parent is, the spouse is about 1 inch taller, in the sample. |
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C. The slope is 0.25. On average, for each inch taller a parent is, the spouse is about 0.25 inches taller, in the sample. |
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D. The slope is 48.40. On average, for each inch taller a parent is, the spouse is about 0.25 inches taller, in the sample. |
33 The Webster University librarian believes that more than 60% of the books checked out by students was fictional material. In a random sample of 1000 students who checked books out in the last year, 628 checked out fictional material. Hypothesis level of significance is 0.05? State the null and alternative hypothesis:
Answer
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A. H0: p1 = 0.60 : HA: p1 ≠ 0.60 |
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B. H0: p1 < 0.60 HA: p1≥ 0.60 |
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C. H0: p1 > 0.60 HA: p1≤0.60 : |
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D. H0: p1 ≠ p2 HA: p1= p2 : |
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34 Are average SAT scores higher in schools where a smaller percentage of graduating students take the test? To answer this question 10 schools are sampled and the average SAT and percentage of students taking the test were recorded. 2002 SAT results of regional high schools were sampled and the data is given below. Use that data to test if there is a relation between the proportion of seniors that take the test and the average SAT scores. At 95% confidence level.
|
2002 SAT results of a sample of Western North Carolina High Schools. |
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Mean SAT scores |
1106 |
1040 |
1013 |
1066 |
1061 |
1075 |
1058 |
997 |
1014 |
965 |
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Percent tested |
61 |
59 |
44 |
54 |
72 |
74 |
80 |
32 |
49 |
23 |
Se Set up the Hypotheses: H0: β1 = 0 and HA: β1 ≠ 0, what is the Fstat and pvalue
Answer
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A. A. Fstat=6.0, pvalue= 3.0E-08 |
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B. Fstat= 0.039, pvalue=0.039 |
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C. Fstat=16.0, pvalue=0.0039 |
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D. Fstat=0.039, pvalue=3.0E-08 |
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35 |
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46. Are average SAT scores higher in schools where a smaller percentage of graduating students take the test? To answer this question 10 schools are sampled and the average SAT and percentage of students taking the test were recorded. 2002 SAT results of regional high schools were sampled and the data is given below. Use that data to test if there is a relation between the proportion of seniors that take the test and the average SAT scores. At 95% confidence level.
Summarize the data:
Answer
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36 A researcher wanted to know if there was a difference in the percentage of cartoons that men and woman consider funny. α=0.05. He accumulated the following data.
Women: 84, 97, 58, 90,
Men: 88, 90, 52, 97, 86,
1. Using information from above, what is the t-stat and p value?
Answer
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1. A. P value=0.032, t=0.092 |
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B. P value=0.06, t=+0.08 |
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C. P value=0.05, t=-0.07 |
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D. P value=0.023, t=-0.03 |
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37 The following is data showing US traffic fatalities and years.
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Year |
Fatal Crashes |
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1994 |
29,757 |
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1995 |
30,296 |
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1996 |
30,862 |
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1997 |
34,172 |
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1998 |
37,435 |
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1999 |
38,648 |
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2000 |
39,252 |
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2001 |
38,444 |
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2002 |
38,477 |
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2003 |
38,491 |
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2004 |
37,862 |
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2005 |
37,526 |
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2006 |
37,140 |
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2007 |
37,107 |
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2008 |
37,324 |
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2009 |
37,494 |
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2010 |
37,241 |
1. What is the predicted fatalities for year 2011?
Answer
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A. 39,781.4 |
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B. 42,268 |
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C. 23,000 |
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D. It cannot be predicted based on small R² value |
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38 A research study was conducted to examine the clinical efficacy of a new antidepressant. Depressed patients were randomly assigned to one of three groups: a placebo group, a group that received a low dose of the drug, and a group that received a moderate dose of the drug. After four weeks of treatment, the patients completed the Beck Depression Inventory. The higher the score, the more depressed the patient. The data are presented below. Compute the appropriate test using α=0.01.
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Placebo |
Low Dose |
Moderate Dose |
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38 |
22 |
14 |
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47 |
19 |
26 |
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39 |
8 |
11 |
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25 |
23 |
18 |
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42 |
31 |
5 |
Ho: There will be no difference in depression levels between the three groups.
Ha: There will be a difference somewhere in depression levels between the three levels of drug groups.
What is your F value and Fcrit?
Answer
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A. 12.75, 7.42 |
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B. 790.8, 1483 |
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C. 11.26, 6.93 |
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D. 742.66, 6.49 |
39 Researchers can sometimes exploit the fact that measuring the same person twice (usually before and then after applying a treatment) results in positively correlated values. Studies that use this structure illustrate_________________
Answer
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A. Confounding variables |
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B. Random assignment |
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C. Blocking |
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D. Matched-pairs design |
40 Suppose the Acme Drug Company develops a new drug, designed to prevent colds. The company states that the drug is equally effective for men and women. To test this claim, they choose a simple random sample of 100 women and 200 men from a population of 100,000 volunteers. At the end of the study, 38% of the women caught a cold; and 51% of the men caught a cold. Summarize the results.
Answer
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A. Reject the null hypothesis |
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B. Accept the null hypothesis |
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C. Not enough data to accept or reject hypothesis |
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41 Neuroscience researchers examined the impact of environment on rat development. Rats were randomly assigned to be raised in one of the four following test conditions: Impoverished (wire mesh cage - housed alone), standard (cage with other rats), enriched (cage with other rats and toys), super enriched (cage with rats and toys changes on a periodic basis). After two months, the rats were tested on a variety of learning measures (including the number of trials to learn a maze to a three perfect trial criteria), and several neurological measure (overall cortical weight, degree of dendritic branching, etc.). The data for the maze task is below. Compute the appropriate test for the data provided below. Compute the appropriate test using α=0.01.
|
Impoverished |
Standard |
Enriched |
Super Enriched |
|
22 |
17 |
12 |
8 |
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19 |
21 |
14 |
7 |
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15 |
15 |
11 |
10 |
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24 |
12 |
9 |
9 |
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18 |
19 |
15 |
12 |
Ho: Environment will have no impact on learning ability as operationalized by maze performance in rats.
Ha: Environment will have an impact on learning ability as operationalized by maze performance in rats.
Are there any significant differences between the four testing conditions?
Answer
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A. . No there is no significant difference groups |
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B. Yes there is a significant difference between the groups |
42 Use the following information to answer the question. A statistics professor is interested in learning whether there is a positive association between number of posts by online students on a message board and the final class average in an online statistics course. The computer output below shows the results from a regression model in which the final class average was predicted by the number of message board posts. Assume that the conditions of the linear regression model are satisfied.
Choose the correct null and alternative hypothesis to test whether there is an association between final class average and number of message board posts.
Answer
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A. Ho: There is a linear association between the number of message board posts and the final class average. Ha: There is no linear association between the number of message board posts and the final class average. |
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B. Ho: The correlation is positive. Ha: The correlation is zero. |
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C. Ho: There is no linear association between the number of message board posts and the final class average. Ha: There is a positive linear association between the number of message board posts and the final class average. |
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E. None of these.
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43 The alternative hypothesis, Ha , is the research hypothesis. It is usually a statement about the value of a parameter that we hope to demonstrate is true.
Answer
True False
44 Suppose the Acme Drug Company develops a new drug, designed to prevent colds. The company states that the drug is equally effective for men and women. To test this claim, they choose a simple random sample of 100 women and 200 men from a population of 100,000 volunteers. At the end of the study, 38% of the women caught a cold; and 51% of the men caught a cold. What is the p-value?
Answer
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A. 0.017 |
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B. 0.034 |
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C. 0.068 |
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D. 0.020 |
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45 An insurance company is reviewing its current policy rates. When originally setting the rates they believed that the average claim amount was $1,800. They are concerned that the true mean is actually higher than this, because they could potentially lose a lot of money. They randomly select 40 claims, and calculate a sample mean of $1,950. Assuming that the standard deviation of claims is $500, and set α = 0.05, test to see if the insurance company should be concerned. What is the test statistic?
Answer
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1. A. Z=1.65 |
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B. Z=2.25 |
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C. Z=1.89 |
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D. Z=1.75 |
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46 1. The following is data showing US traffic fatalities and years.
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Year |
Fatal Crashes |
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1994 |
29,757 |
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1995 |
30,296 |
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1996 |
30,862 |
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1997 |
34,172 |
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1998 |
37,435 |
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1999 |
38,648 |
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2000 |
39,252 |
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2001 |
38,444 |
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2002 |
38,477 |
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2003 |
38,491 |
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2004 |
37,862 |
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2005 |
37,526 |
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2006 |
37,140 |
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2007 |
37,107 |
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2008 |
37,324 |
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2009 |
37,494 |
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2010 |
37,241 |
What is the R2 value?
Answer
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A. R² = 0.765 |
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B. R² = 0.397 |
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C. R² = 0.465 |
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D. R² = 0.239 |
47 A researcher wanted to know if there was a difference in the percentage of cartoons that men and woman consider funny. α=0.05. He accumulated the following data.
Women: 84, 97, 58, 90,
Men: 88, 90, 52, 97, 86,
1. What is the summation of the results from previous question?
Answer
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A. Do not reject the null hypothesis |
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B. Reject the null hypothesis |
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C. Not enough information to make a conclusion |
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48 Suppose a consumer product researcher wanted to find out whether a highlighter lasted less than the manufacturer's claim that their highlighters could write continuously for 14 hours. The researcher tested 40 highlighters and recorded the number of continuous hours each highlighter wrote before drying up. Test the hypothesis that the highlighters wrote for less than 14 continuous hours. Following are the summary statistics:
xbar =13.6 hours, s =1.3 hours
Report the test statistic, p-value, your decision regarding the null hypothesis, and your conclusion about the original claim. Round all values to the nearest thousandth.
Answer
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A. z = 1.946; p = 0.029; Reject the null hypothesis; there is strong evidence to suggest that the highlighters last less than 14 hours. |
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B. t = -1.946; p = 0.029; Fail to reject the null hypothesis; there is not strong evidence to suggest that the highlighters last less than 14 hours. |
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C. z = 1.946; p = 0.974; Fail to reject the null hypothesis; there is not strong evidence to suggest that the highlighters last less than 14 hours. |
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D. t = -1.946; p = 0.029; Reject the null hypothesis; there is strong evidence to suggest that the highlighters last less than 14 hours. |
49 Use the following information to answer the question. A random sample of 30 married couples were asked to report the height of their spouse and the height of their biological parent of the same gender as their spouse. The output of a regression analysis for predicting spouse height from parent height is shown. Assume that the conditions of the linear regression model are satisfied.
Test the hypothesis that the slope is zero (significance level is 0.05), then choose the correct decision regarding the null hypothesis and the statement that correctly summarizes the conclusion.
Answer
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A. Fail to reject Ho. We don't have enough evidence to reject a slope of zero which is an indication that no linear association exists between parent height and spouse height.
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B. Reject Ho. We don't have enough evidence to reject a slope of zero which is an indication that no linear association exists between parent height and spouse height.
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C. Reject Ho. There is enough evidence to reject a slope of zero which is an indication that a linear association exists between parent height and spouse height.
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D. Fail to reject Ho. There is enough evidence to reject a slope of zero which is an indication that a linear association exists between parent height and spouse height. |
