10 STAT Questions

profilewillj-1
Home>Homework Answsers>Mathematics homework help

1.The standard deviation of the diameter at breast height, or DBH, of the slash pine tree is less than one inch. Identify the Type I error. (Points : 1)

      [removed] Fail to support the claim σ < 1 when σ < 1 is true.
      [removed] Support the claim  μ < 1 when μ = 1 is true.
      [removed] Support the claim σ < 1 when σ = 1 is true.
      [removed] Fail to support the claim μ < 1 when μ < 1 is true.

2. Use the following sample sizes and numbers of successes for this question. 

Medical researchers reviewing the risk of death for elderly patients taking dementia drugs found the following data. Assume a .05 significance level for testing the claim that the proportions are not equal. Also, assume the two simple random samples are independent and that the conditions np ≥ 5 and nq ≥ 5 are satisfied.


 

 

Dementia Drugs

Placebo

Number of patients

500

450

Total deaths

23

12


 
Construct a 95% confidence interval estimate of the odds ratio of the odds for death in the placebo group to the odds for death in the dementia drugs group. Give your answer with two decimals, e.g., (12.34,56.78) (Points : 0.5)

      [removed]

3. Scientists, researching large woody debris (LWD), surveyed the number of LWD pieces from aerial photos taken annually for the past 35 years at two different sites. Over the 35 years of photos examined, the first site had a mean number of LWD pieces per hectare per year (LWD/ha/yr) of 3.7 pieces with a standard deviation of 1.9. The second site had a mean number of LWD/ha/yr of 4.3 with a standard deviation of 2.4. Assume a .05 significance level for testing the claim that the mean LWD/ha at the first site had less than the mean LWD/ha/yr at the second site. Also, assume the two samples are independent simple random samples selected from normally distributed populations, but do not assume that the population standard deviations are equal.

Find the t test statistic. Give your answer with two decimals, e.g., 9.87 (Points : 0.5)

      [removed]

4.

Given: There is a linear correlation coefficient very close to 0 between black willow tree cuttings monitored for survival at 7 days and black willow tree cuttings monitored for survival at 14 days. Identify the choice below that contains a conclusion with a common correlation error. (Points : 1)

      [removed] Conclusion: there is not a linear relationship between the survival of black willow tree cuttings at 7 days and the survival of black willow tree cuttings at 14 days
      [removed] Conclusion: the survival of black willow tree cuttings at 7 days is not related in any way to the survival of black willow tree cuttings at 14 days
      [removed] Conclusion: an increase in the survival of black willow tree cuttings at 7 days is not linearly related to the survival of black willow tree cuttings at 14 days
      [removed] Conclusion: a decrease in the survival of black willow tree cuttings at 7 days is not linearly related to a decrease in the survival of black willow tree cuttings at 14 days 
 

5. The paired data consist of the temperatures (in °F ) on randomly chosen days and the amount a certain kind of plant grew (in millimeters).

 

Temp

60

73

42

88

66

77

90

63

55

96

Growth

70

80

40

94

79

86

93

71

70

97


 
Find the predicted growth of the plant in mm if the temperature is 75° F . Give your answer with one decimal, e.g., 98.7 . (Points : 0.5)

      [removed]

6. Using a .01 significance level, test the claim that the proportions of people who favor/oppose pro-choice on the abortion issue are the same for the males and females.

 
Gender

 

 

Male

Female

Favor Pro-Choice

65

120

Oppose Pro-Choice

42

38


 
Do you reject the null hypothesis, at the .01 significance level? Enter Y for yes (reject), N for no (fail to reject). (Points : 0.5)

      [removed]

7.

The table represents results from an experiment with patients afflicted with eczema on both arms. Each patient was treated with an immune modulator cream on one arm and a topical steroid cream on the other arm. Using a .05 significance level, apply McNemar's test to test the following claim: The proportion of patients with no cure on the immune modulator treated arm and a cure on the topical steroid treated arm is the same as the proportion of patients with a cure on the immune modulator treated arm and no cure on the topical steroid treated arm.

 

 

 

Immune Modulator Cream

 

 

 

Cure

No Cure

Topical Steroid

Cure

25

11

Cream

No Cure

42

22


 
Do you reject the null hypothesis, at the .05 significance level? Enter Y for yes (reject), N for no (fail to reject). (Points : 0.5)

      [removed]

8. Geneticists studying carriers of genetic diseases followed subjects subdivided by race. Researchers randomly selected seven patients per race who had been identified as carrying a certain gene for a genetic disease; these patients were followed to determine the number of their siblings who also carried the gene for the genetic disease. Use a One-Way ANOVA at a .05 significance level to test the claim that the means from the different races are not all the same.

 

Caucasian

African-American

Other

2

0

0

3

0

1

3

1

2

3

2

2

4

2

2

5

2

3

5

4

4


 
Do you reject the null hypothesis, at the .05 significance level? Enter Y for yes (reject), N for no (fail to reject). (Points : 0.5)

      [removed]

9.

Assuming calculations for a One-Way ANOVA with equal sample sizes, if each data value in one of the samples is increased by a fixed amount, then any change in the F test statistic and the P-value is attributable only to the change in the sample variances. (Points : 1)

      [removed] True 
      [removed] False 

10. Use the following technology display from a Two-Way ANOVA to answer this question. Biologists studying habitat use in Lepidopteran moths measured the number of savannah moths found at three randomly selected prairie sites with two potential habitat interferences (expansion of row crops and grazing). Use a .05 significance level.

 

Source

Df

SS

MS

F

P

Site

2

.1905

.0952

.0381

.9627

Habitat

1

304.0238

304.0238

121.6095

.0000

Site*Habitat

2

.1905

.0952

.0381

.9627


 
Do you reject the null hypothesis anbout the habitat effect, at the .05 significance level? Enter Y for yes (reject), N for no (fail to reject). (Points : 0.5)

      [removed]

  • 11 years ago
  • 10
Report issue
Answer(0)