Suppose that simple random samples of college freshman are selected from two universities – 25 students from school A and 20 students from school B. On a standardized
test, the sample from school A has an average score of 990 with a standard deviation of 100. The sample from school B has an average score of 950 with a standard
deviation of 90. What is the 95% confidence interval for the difference in test scores at the two schools, assuming that test scores came from normal distributions in
both schools?
