A study was designed to investigate the effects of two variables - (1) a studentʹs level of mathematical anxietyand (2) teaching method - on a studentʹs achievement in a mathematics course. Students who had a low levelof mathematical anxiety were taught using the traditional expository method. These students obtained a meanscore of 460 with a standard deviation of 50 on a standardized test. Assuming a bell-shaped distribution, whatpercentage of scores exceeded 360?
A) approximately 97.5%
B) approximately 95%
C) approximately 2.5%
D) approximately 84%

Question

Quizplus · Accepted Answer

The mean score is 460 and the standard deviation is 50. The z-score for a score of 360 is (360 - 460) / 50 = -2.0. The percentage of scores that exceed 360 is the area under the normal curve to the right of z = -2.0, which is approximately 97.5%.

A Study Was Designed to Investigate the Effects of Two