1.A random sample of 8 adults aged 30 years were asked how much they spent on medical costs in the year 2009. Using the following data, compute the sample mean, the sample standard deviation, the sample median, and the first and third quartiles.

17527522005201704293701300

2.What is the appropriate statistical test to assess whether there is an association between obesity status (normal weight, overweight, obese) and 5-year incident cardiovascular disease (CVD)? Suppose each participant's obesity status (category) is known along with whether they develop CVD over the next 5 years or not.

3.A small pilot study is run to compare a new drug for chronic pain to one that is currently available.Participants are randomly assigned to receive either the new drug or the currently available drug and to report improvement in pain on a 5-point ordinal scale: 1 = Pain is much worse, 2 = Pain is slightly worse, 3 = No change, 4 = Pain improved slightly, 5 = Pain much improved. Is there a significant difference in self-reported improvement in pain? Use the Mann-WhitneyUtest with a 5% level of significance.

NewDrug:453342

Standard Drug:234123

4.A small pilot study is conducted to investigate the effect of a nutritional supplement on total body weight. Six participants agree to take the nutritional supplement. To assess its effect on body weight, weights are measured before starting the supplementation and then after 6 weeks. The data are shown below. Is there a significant increase in body weight following supplementation? Run the test at a 5% level of significance.

Subject

Initial Weight

Weight after 6 Weeks

1

155

157

2

142

145

3

176

180

4

180

175

5

210

209

6

125

126

5.A study is run comparing HDL cholesterol levels between men who exercise regularly and those who do not. The data are shown below.

Regular Exercise

N

Mean

Std Dev

Yes

35

48.5

12.5

No

120

56.9

11.9

Generate a 95% confidence interval for the difference in mean HDL levels between men who exercise regularly and those who do not.

6.Peak expiratory flow (PEF) is a measure of a patient's ability to expel air from the lungs. Patients with asthma or other respiratory conditions often have restricted PEF. The mean PEF for children free of asthma is 306. An investigator wants to test whether children with chronic bronchitis have restricted PEF. A sample of 50 children with chronic bronchitis is studied, and their mean PEF is 251 with a standard deviation of 71. When you run the appropriate test at= 0.05, the appropriate conclusion to whether there statistical evidence of a lower mean PEF in children with chronic bronchitis is?

7.How many subjects would be needed to ensure that a 95% confidence interval estimate of BMI had a margin of error not exceeding 3 units?

282137382428384727323643

8.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.

282137382428384727323643