An instructor has given his final exam,and scores are approximately normally distributed.Nancy scores a 90 and Ronald scores a 75.The characteristics of the distribution are as follows:
= 85,
S² = 36.Approximately what percentage of scores falls at or between Nancy's and Ronald's scores?

Question

Quizplus · Accepted Answer

The z-score for Nancy is (90-85)/6 = 0.83, and the z-score for Ronald is (75-85)/6 = -1.67. The area under the normal curve between these two z-scores is approximately 0.75, or 75%.

An Instructor Has Given His Final Exam,and Scores Are Approximately