Question 13.

A medical researcher wishes to see whether the variance of the heart rates (in beats per minute) of smokers is different from the variance of heart rates of people who do not smoke. Two samples are selected, and the data are shown. Using = 0.05, is there enough evidence to support the claim? Assume the populations are normally distributed.

Sample size 25 18 Sample variance 36 10

(a) (2 pts) State H0 and Ha

(b) (4 pts) Calculate the test statistic

10pts

Smokers Nonsmokers

(c) (2 pts) Find critical value(s)and make a decision

(d) (2 pts) State conclusion.