The developer in Exercise 1 hires an assistant to collect a random sample of houses from each neighborhood and finds that the summary statistics for the two neighborhoods look as follows:

Neighborhood 1Neighborhood 2

n1 = 30 ........ n2 = 35

y1 = 57.2 yrs ....... y2 = 47.6 yrs

s1 = 7.51 yrs ....... s2 = 7.85 yrs

a) Find the estimated mean age difference between the two neighborhoods.

b) Find the standard error of the estimated mean difference.

c) Calculate the t-statistic for the observed difference in mean ages assuming that the true mean difference is 0.