14. The following are body mass index (BMI) scores measured in 12 patients who are free of diabetes and are participating in a study of risk factors for obesity. Body mass index is measured as the ratio of weight in kilograms to height in meters squared. Generate a 95% confidence interval estimate of the true BMI.

25 27 31 33 26 28 38 41 24 32 35 40

15. The mean body mass index (BMI) in patients free of diabetes was reported as 28.2. An investigator conducting the study hypothesizes that the BMI in patients free of diabetes is higher. Based on the data, is there evidence that the BMI is significantly higher than 28.2? Use a 5% level of significance.

25 27 31 33 26 28 38 41 24 32 35 40

Ahead: Tests with One Sample, Continuous Outcome

Subject: Chapter 7

16. Using the data presented below, a) construct a 95% confidence interval for the mean PEF in children without chronic bronchitis; b) determine how many children would be required to ensure that the margin of error in (a) does not exceed 10 units.

Group	Number of Children	Mean PEF	Std Dev PEF
Chronic Bronchitis	25	281	68
No Chronic Bronchitis	25	319	74