Question

Each year, thousands of college seniors take the Graduate Record Examination (GRE). Assume the scores are transformed so they have a mean of 600 and a standard deviation of 150. Furthermore, the scores are known to be normally distributed. Determine the percentage of students that score 475 or greater, below 750, and either less than 750 or more than 800?

Answer 1

780

Answer 2

Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to those Z scores.

For either-or probabilities, add the individual probabilities.