A study was designed to investigate the effects of two variables - (1)a studentʹs level of mathematical anxiety and (2)teaching method - on a studentʹs 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 400 with a standard deviation of 40
On a standardized test. Assuming no information concerning the shape of the distribution is
Known, what percentage of the students scored between 320 and 480?
A)at least 89%
B)at least 75%
C)approximately 95%
D)approximately 68%

Question

Quizplus · Accepted Answer

According to Chebyshev's theorem, at least 75% of data falls within two standard deviations from the mean for any distribution. Here, 320 and 480 are two standard deviations away from the mean of 400 (mean ± 2*40).

A Study Was Designed to Investigate the Effects of Two