1. The population of IQ scores forms a normal distribution with a mean of = 100 and = 15. For a random sample of n = 25 people, what is the sample mean associated with the bottom 20% of the distribution?

2. For random samples of size n = 25, selected from a normal distribution with a mean of = 50 and = 20, find the range of sample means that define the middle 95% of the distribution of sample means.