High blood cholesterol levels increase the risk of heart disease. Young women are generally less afflicted with high cholesterol than other groups. The cholesterol levels for women aged 20 to 34 years follow an approximately normal distribution with mean 185 milligrams per deciliter (mg/dl) and standard deviation 39 mg/dl.

1. (4 points) Cholesterol levels above 240 mg/dl demand medical attention. What percent of young women have levels above 240 mg/dl? Calculate the z-score and probability.
2. (8 points) Levels above 200 mg/dl are considered borderline high. What percent of young women have blood cholesterol between 200 and 240 mg/dl? Calculate the z-scores and probability.
3. (8 points) Among a random sample of 150 women in this age group, what is the probability that no more than 5 women have cholesterol levels that demand medical attention?