Question

1. High cholesterol levels are known to be a major factor in the development of heart disease. A study was conducted to compare the cholesterol levels of men and women in a similar age group. Random samples of males and females in this age group were taken from the general population and their cholesterol levels were measured. Partial results from the study are given below.

Sample Size Male 80 Female 75

Sample Mean 192, 195

Sample Stdev 40.2, 37.5

1. (a) Given that the samples are independent what procedure is appropriate testing a hypothesis comparing the population means? Explain. [Note that no information is given about the populations from which the samples came]

2. (b) Use the procedure chosen in (a) to test at a = .05 if there is sufficient evidence that the mean cholesterol level is higher for women. Do this two ways: (1) by setting up a rejection region; (2) by finding the P-value.

Answer 1

a) Since we have no information about the population from which the sample has taken from but the sample size is greater than 30 for both Male & Female. So, to test a hypothesis to comparing the population means one can use the two-sample Z-test. cdeaA

b) H0: Mean cholesterol level for Men & women is the same.

H1: Mean cholesterol level is higher for women as compared to the man.