Refer to Exercise 10.78. Now answer the questions of parts (a) and (b) there without assuming that

Question:

Refer to Exercise 10.78. Now answer the questions of parts (a) and (b) there without assuming that the standard deviations are the same for the two populations but under the following two situations.
a. Using the sample standard deviations given in Exercise 10.78.
b. Using sample standard deviations of $7.17 and $15.80 for families of four and families of five, respectively.