Assume that you have a sample of n = 7, with the sample mean X = 42, and a sample standard deviation of S = 5, and you have an independent sample of n = 17 from another population with a sample mean of X = 31, and the sample standard deviation S = 8. Construct a 90% confidence interval estimate of the population mean difference between and 2. Assume that the two population variances are equal. (Round to two decimal places as needed.)