A Study Was Designed to Investigate the Effects of Two

Multiple Choice

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%