Q1. Average adult American are about one inch taller , but nearly a whopping 25 pounds heavier than they were in 1960, according to a new report from the centers for disease control and prevention (CDC) . The bad news, says CDC is that average BMI (body mass index, a weight -for - height formula used to measure obesity) has increased among adults from approximately 25 in 1960 to 28 in 2002. Boston is considered one of America's healthiest cities in the weight gain since 1960 similar in Boston? A sample of n =25 adults suggested a mean increase of 17 pounds with a standard deviation of 8.6 pounds. Is Boston statistically significantly different in terms of weight gain since 1960?

Apply the appropriate test at a 5% level of significance.

A. Critical t value: +/-

B. Computed statistic

C. Based on comparing the computed statistic to the critical value which of the following is (are) true?

a) There is significant evidence, alpha = 0.05, that the BMI for Boston residents is significantly different than 25.
b) There is not significant evidence, alpha =0.05, that the BMI for Boston residents is significantly different than 25.
c) Statistically speaking the difference between the BMI for Boston residents and BMI of 25 is 0.
d) B & C.

Q2) A study is conducted comparing HDL Cholesterol levels between men who exercise regularly and those who do not. The data are shown below. Generate a 95% confidence interval for the difference in mean HDL levels between men who exercise regularly and those who do not.

A) Z 95% confidence:

B) Upper limit 95% cl

C) Lower limit 95% cl

D) based on examination of the upper and lower limits of the confidence interval for the mean HDL levels which of the following is (are) true

a) There is statistical evidence of a difference in mean HDL levels between men who exercise and those who do not.
b) There is not statistical evidence of a difference in mean HDL level of men who exercise regularly and those who do not.
c) The confidence interval contains the mean HDL level
d) B & C

Regular Exercise     N         Mean      Standard Deviation
Yes                         35         48.5               12.5
No                         120        56.9               11.9.