In each of Exercises, we have provided summary statistics for independent simple random samples from two populations. In each case, use the nonpooled t-test and the nonpooled t-interval procedure to...

In each of Exercises, we have provided summary statistics for independent simple random samples from two populations. In each case, use the nonpooled t-test and the nonpooled t-interval procedure to conduct the required hypothesis test and obtain the specified confidence interval.

x1 = 20, s1 = 2, n1 = 30, x2 = 18, s2 = 5, n2 = 40
a. Right-tailed test, a = 0.05 b. 90% confidence interval