1. For a normal distribution with a mean of u = 85 and a standard deviation of o = 20, find the proportion of the population corresponding to each of the following a. Scores greater than 89 b. Scores less than 72 c. Scores between 70 and 100 2. Find the z-score boundaries that separate a normal distribution as described in each of the following. The middle 20% from the 80% in the tails b. The middle 25% from the 75% in the tails The middle 70% from the 30% in the tails d. The middle 90% from the 10% in the tails