Scores at a local high school on the American College Testing (ACT) college entrance

exam follow the normal distribution with a mean of 18 and a standard deviation of 8. A

guidance counselor takes a random sample of 20 students and calculates the mean score,

A. Calculate the mean and standard deviation of the sampling distribution of Y

B. Interpret the standard deviation from part (a).

C. Find the probability that a sample of 20 students has a mean score of 19.5 or more.