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 with a standard deviation of on a standardized test. Assuming a​ mound-shaped and symmetric​ distribution, in what range would approximately ​% of the students​ score?

Solution using the Empirical Rule, which is explained here.

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

Approximately 68% of the measures are within 1 standard deviation of the mean.

Approximately 95% of the measures are within 2 standard deviations of the mean.

Approximately 99.7% of the measures are within 3 standard deviations of the mean.

The question is incomplete, but you solve this using the Empirical Rule.

its a little blurry tbh

step-by-step explanation:

option a.

step-by-step explanation:

if you look closely at the graph, we can notice that the function is not defined at two different points.

if you look at functions b and c, you will notice that both functions are not defined at just one point. the function b is not defined at x= -5/2 and function c is not defined at x=-5. both options are discarded, given that our function should not be defined at two fiferent points.

now, if you look closely at the graph you will notice that the function sketched is not defined at x=5 and x=-2.