The distribution of test scores in a large statistics class is approximately Normal with mean 74 points and standard deviation 6.5 points.

1. 68% of students scored between what two values?
2. Approximately what percent of the students failed the test (i.e. scored below 60 points)
3. Approximately what percent of the students scored above 70 points?
4. What score would be at the 86th percentile? In other words what score separates the top 14% from the bottom 86%?
5. What percent of the students got a C or a B? (Between 70 and 90)
6. Suppose you and 4 friends compared your exam scores. What is the probability that the average score of your group of 5 is less than 80?