The management of a distributor was interested in whether or not the amount of outstanding payables was the same in two offices. To investigate they took a random sample of the customers in one office (office 1) and determined the amount of outstanding payables for those customers. For office 1 there were 15 customers sampled, the sample mean outstanding payables was $290 with a standard deviation of $15. An independent random sample of size 12 from office 2 yielded a sample mean of $250 with a sample standard deviation of $19. a) Find a 95% confidence interval for the difference in the mean outstanding payables for these 2 offices