For the data in Exercise 1, we want to test the null hy- pothesis that the mean age of houses in the two neighborhoods is the same. Assume that the data come from a population that is Normally distributed.
a) Using the values you found in Exercise 1, find the value of the t-statistic for the difference in mean ages for the null hypothesis.
b) Calculate the degrees of freedom from the formula in the footnote of page 402.
c) Calculate the degrees of freedom using the rule that df = min(n1 - 1, n2 - 1).
d) Find the P-value using the degrees of freedom from part b. (You can either round the number of df and use a table or use technology or a website).
e) Find the P-value using the degrees of freedom from part d.
f) What do you conclude at a = 0.05?