Suppose that the mean score for the mathematics test cited in Problem 7 is 610. What is the probability that a random sample of 225 students will have a mean score of more than 625? Less than 600?

Data from Problem 7

Based upon extensive data from a national high school educational testing program, the standard deviation of national test scores for mathematics was found to be 120 points. If a sample of 225 students are given the test, what would be the standard error of the mean?