1. The average age of vehicles registered in the United States is 96 months. Assume the population is normally distributed with a standard deviation of 15 months. Find the probability that the average age of a sample of 36 vehicles is between 98 and 100 months?
2. If a normally distributed group of test scores have a mean of 70 and a standard deviation of 12. Find the percentage of scores that will fall below 50.