1.The commute times to school were collected from samples of 36 males and 49 females from off-campus and the results are tabulated as follows:

sample	size	mean time (in min)	std. dev. time
Male	36	15.6	2.34
Female	49	14.4	1.28

a. Compute the degrees of freedom of the sampling distribution

b. Find a 90% confidence interval estimate for the difference in the true mean commute times (12)

c. Is there sample evidence to conclude that the true mean time to commute for males is greater than that of the females at the 0.05 level of significance?

2. Write briefly about the sampling distribution of X1bar - X2bar mentioning all essential points