Assume we have a population of scores with mean (?) of 975 and standard deviation (?) of 15. Suppose that the distribution is normal. Give answers to the following questions:
a. What percentage of population will lie between 960 and 990?
b. What percentage of population will lie below 975?
c. What percentage of population will lie below 990?
d. What two values of X (the counts) would have the middle 50 percent of scores?