Posted by **Kim** on Thursday, May 3, 2012 at 11:10am.

The serum cholesterol levels in men aged 18 to 24 are normally distributed with a mean of 178.1 and a standard deviation of 40.7. A group of 9 men aged 18 to 24 randomly selected.

1. Find the probability that there are at least 2 men in the group whose serum cholesterol level is at most 230.

2. Suppose 90% of men's serum cholesterol level is less than c. What is the value of c?