13.2 We are interested in whether industrial firms or service firms growth faster over the last five years. Studies and theoretical considerations suggest that there should be a difference. Perform the test at the 5% significance level, considering all relevant steps. The following values are available: x¯i = 6.35, si = 5.03, ni = 34, x¯s =

7.49,ss = 5.77, ns = 66.