C10. The number of hours people work each week varies widely for many reasons. Using the GSS18SSDS-A, you find that the mean number of hours worked last week was 41.32, with a standard deviation of 15.28 hours, based on a sample size of 875.

1. Assume that hours worked are approximately normally distributed in the sample.

What is the probability that someone in the sample will work 60 hours or more in a week? How many people in the sample should have worked 60 hours or more?

2. What is the probability that someone will work 30 hours or fewer in a week (i.e., work part-time)? How many people does this represent in the sample?

3. What number of hours worked per week corresponds to the 60th percent?