# STATS

teacup2013

 The ones that are highlighted I did them just want to make sure they are correct.    Question 9 of 17 2.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

A survey of employees at a company finds that 32 of the 88 employees who drive to work were ever late during the past year, and 18 of the 64 employees who took public transportation were ever late during the past year.  At
α = 0.10, is there a difference between the proportion of employees who drove who were ever late and the proportion of employees who took public transportation who were ever late?

Find the test value for the difference in the proportion of employees who were ever late for work in the past year.

What is your decision for this test?

1. The test value is greater than the critical value of 1.960.
2. The test value is less than the critical value of 1.645.
3. The test value is greater than the critical value of 1.282.
4. The test value is less than the critical value of 1.960.

 Question 10 of 17 1.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

The marketing manager of a large supermarket chain would like to determine the effect of shelf space (in feet) on the weekly sales of international food (in hundreds of dollars). A random sample of 12 equal –sized stores is selected, with the following results:

 Store Shelf Space(X) Weekly Sales(Y) 1 10 2.0 2 10 2.6 3 10 1.8 4 15 2.3 5 15 2.8 6 15 3.0 7 20 2.7 8 20 3.1 9 20 3.2 10 25 3.0 11 25 3.3 12 25 3.5

Based on these data, what are the least squares regression coefficients of the Y-intercept (a) and slope (b)?

Place your answers, rounded to 3 decimal places , in the blanks provided.

a = [removed]         b = [removed]

 Question 11 of 17 1.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

The marketing manager of a large supermarket chain would like to determine the effect of shelf space (in feet) on the weekly sales of international food (in hundreds of dollars). A random sample of 12 equal –sized stores is selected, with the following results:

 Store Shelf Space(X) Weekly Sales(Y) 1 10 2.0 2 10 2.6 3 10 1.8 4 15 2.3 5 15 2.8 6 15 3.0 7 20 2.7 8 20 3.1 9 20 3.2 10 25 3.0 11 25 3.3 12 25 3.5

Find the equation of the regression line for these data.  What is the value of the standard error of the estimate?  Place your answer, rounded to 3 decimal places, in the blank.  Do not use a dollar sign.  For example, 0.345 would be a legitimate entry.  [removed]

 Question 12 of 17 1.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

Q-Mart is interested in comparing its male and female customers. Q-Mart would like to know if the amount of money spent by its female charge customers differs, on average, from the amount spent by its male charge customers. To answer this question, an analyst collected random samples of 25 female customers and 22 male customers.

Based on these samples, on average, the 25 women charge customers spent \$102.23 and the 22 men charge customers spent \$86.46. Moreover, the sample standard deviation of the amount charged by the 25 women was \$93.393, and the sample standard deviation of the amount charged by the 22 men was \$59.695.

Suppose, using a 10% level of significance, you wish to know if there is sufficient evidence for Q-Mart to conclude that, on average, the amount spent by women charge customers differs from the amount spent by men charge customers. That is suppose you wish to test

H0:   versus  H1:

Assuming that the amounts spent by male and female charge customers at Q-Mart are normally distributed, based on the procedure advocated by Bluman, what is the test value that you would use to conduct this test of hypothesis? Place your answer, rounded to 3 decimal places, in the blank. For example, 0.123 would be a legitimate entry.  [removed]

 Question 13 of 17 1.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

Q-Mart is interested in comparing its male and female customers. Q-Mart would like to know if the amount of money spent by its female charge customers differs, on average, from the amount spent by its male charge customers.

To answer this question, an analyst collected random samples of 25 female customers and 22 male customers. Based on these samples, on average, the 25 women charge customers spent \$102.23 and the 22 men charge customers spent \$86.46. Moreover, the sample standard deviation of the amount charged by the 25 women was \$93.393, and the sample standard deviation of the amount charged by the 22 men was \$59.695.

Suppose, using a 10% level of significance, you wish to know if there is sufficient evidence for Q-Mart to conclude that, on average, the amount spent by women charge customers differs from the amount spent by men charge customers. That is suppose you wish to test

H0:  versus H1:

Assuming that the amounts spent by female and male charge customers at Q-Mart are normally distributed, based on the procedure advocated by Bluman, what is/are the critical values that you would use to conduct this test of hypothesis? Place your answer, rounded to 3 decimal places, in the blank. If there are two critical values, place only the positive value in the blank. For example, 2.035 would be a legitimate entry.   [removed]

 Question 14 of 17 3.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

A professor gives an exam for which there are two versions, A and B.  Each student in the class is given one randomly selected version of the exam.   After the exam, the professor wishes to determine if there is a difference in the level of difficulty of the two versions by determining if there is a significant difference in the mean scores.  Assume
α = 0.05.

 Version A Version B Sample size 45 65 Mean score 8.8 8.2 Sample variance 2.6 2.4

What is the test value for this hypothesis test?

What is/are the critical value(s) for this hypothesis test?  If there are two critical values, give only the positive value.

What is the conclusion for this hypothesis test?  Choose one.

1.  There is not sufficient evidence to show that one version of the exam is more difficult than the other.
2.  There is sufficient evidence to show that one version of the exam is more difficult than the other.

 Question 15 of 17 1.0 Points

When the necessary conditions are met, a two-tail test is being conducted to test the difference between two population proportions. The two sample proportions are  = 0.35 and = 0.42, and the standard error of the sampling distribution of  is 0.054. The calculated value of the test statistic is 1.2963.

 [removed]True [removed]False

• 9 years ago
• 2