Posted by Max on Wednesday, May 25, 2011 at 7:08pm.
This is a question on a study guide for a test tomorrow. How do you do it? Please help
According to the Federal Highway Administration, teenage males drive an average of 10,718 miles each year. Assume the mileage totals are normally distributed with a standard deviation of 3573 miles. For a randomly selected teenage male, find the probability that he drives less than 9,000 miles in a year.

math  MathMate, Thursday, May 26, 2011 at 7:59am
Z=(meanx)/σ
=(107189000)/3573
=0.4808
From tables, probability for x≤9000
=0.50.184
=0.316