In a genetic inheritance study discussed by Margolin, blood was collected from samples of individuals from several ethnic groups, and mean sister chromatid exchange (MSCE) was measured for each individual. We wish to see if there's a difference in average MSCE for the groups labeled "Native American" and "Caucasian." Here's the data:

Native American: 8.50, 9.48, 8.65, 8.16, 8.83, 7.76, 8.63

Caucasian: 8.27, 8.20, 8.25, 8.14, 9.00, 8.10, 7.20, 8.32, 7.70

a. What's the experimental unit? What measurements are taken on the experimental units? Is this a problem with one or two independents samples?

b. Carefully define your parameter of interest and give null and alternative hypotheses for an appropriate t-test.

c. Perform an appropriate t-test, and give your t-statistic, degrees of freedom, and P-value. State any assumptions you make.

d. Give a 95% t-confidence interval for your parameter of interest.

e. The P-value you should get isn't that small. Should we then conclude that there's no difference in average MSCE between Native Americans and Caucasians? Explain why or why not.