A study was designed to investigate the effects of two variables - (1) a student's level of mathematical anxiety and (2) teaching method - on a student's achievement in a mathematics course. Students who had a low level of mathematical anxiety were taught using the traditional expository method. These students obtained a mean score of 290 with a standard deviation of 40 on a standardized test. Assuming a bell-shaped distribution, what percentage of scores exceeded 210?
A) approximately 95%
B) approximately 97.5%
C) approximately 2.5%
D) approximately 84%

Question

Quizplus · Accepted Answer

The score of 210 is two standard deviations below the mean (290 - 2*40 = 210). In a bell-shaped (normal) distribution, about 97.5% of the scores lie above the score that is two standard deviations below the mean.

A Study Was Designed to Investigate the Effects of Two