Question

The GPAs of all students enrolled at a large university have an approximately normal distribution with a mean of 3.02 and a standard deviation of .29. Find the probability that the mean GPA of a random sample of 20 students selected from this university is

2.87 or lower

Answer 1

Find z-score:

z = (2.87 - 3.02)/(.29/√20) = ?

Calculate.

Check a z-table for the probability using the z-score. (Remember that the question is asking for "2.87 or lower" when looking at the table.)

Answer 2

1.103

Answer 3

The GPAs of all students enrolled at a university have an approximately normal distribution with a mean of 3.02 and a standard deviation of 0.29.Calculate the probability that a student chosen at random would obtain the GPA less than 3.10.