In: Statistics and Probability
Investigators studying exercise habits in different regions of the country surveyed a simple random sample of 421 California adults, age 25 - 35, and an independent simple random sample of 377 Massachusetts adults, age 25 - 35.
Among other observations, the investigators noted that
(i) In the CA sample, the average number of hours/week of exercise
was 7.4, with a standard deviation of 3.3;
(ii) In the MA sample, the average number of hours/week of exercise
was 6.7, with a standard deviation of 3.5.
Based on this data, the investigators concluded that CA adults (in this age group) exercise more than MA adults (in this age group).
Use an appropriate test of significance to test the investigators' claim, at the 5% significance level.
(a) State the formal hypotheses in terms of appropriate population parameters.
(b) Find the test statistic and the p-value and explain how you found them (i.e., where the EV and SE come from, what distribution the test statistic follows, etc.)
(c) Summarize your conclusions in terms of the investigators' claim.