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 430 with a standard deviation of 20
On a standardized test. Assuming a non-mound-shaped distribution, what percentage of the
Students scored over 490?
A)approximately 2.5%
B)at most 11%
C)at least 89%
D)at most 5.5%

Question

Quizplus · Accepted Answer

Since the distribution is non-mound-shaped, we cannot use the empirical rule. However, using Chebyshev's inequality, which applies to any distribution, we can determine that at most 11% of the students scored more than 3 standard deviations above the mean (490 is 3 standard deviations above 430).

A Study Was Designed to Investigate the Effects of Two