More Than 1

Essay

More than 1.5 million college-bound high school seniors took the Critical Reading portion of the SAT exam recently. The mean was 503; the standard deviation was 113.
a. What proportion scored 500 or above?
b. Suppose that a university, based on past experience, decided to not admit anyone whose Critical Reading score placed them in the lowest 20 percent of the population. What is that score?
c. What proportion of the population scored between 600 and 700?
d. From 1000 students, how many would be expected to score 700 or more?
e. In working these problems, you began with an assumption about the distribution of Critical Reading test scores. What is that assumption?