Listed below are heights (in.) of fathers and their first sons. The data are from a journal kept by Francis Galton. (See Data Set 6 "Family Heights") Use a 0.05 significance level to test the claim that there is no difference in heights between fathers and their first sons.

Height of Father 72 66 69 70 70 70 70 75 68.2 65

Height of Son 73 68 68 71 70 70 71 71 70.0 63

a. Identify the null and alternative hypotheses

b. Calculate the test statistic. (Note: standard deviation of the differences = 1.863)