He test scores on the Chapter 10 mathematics test have a mean of 52 and a standard deviation of 10. Andrea scored 76 on the test. How many standard deviations from the mean is that?

Step-by-step explanation:

Hello!

The mean is a measurement of central tendency that shows what is the most expected value of the variable. The standard deviation is a measurement of variability, it shows you how distant or dispersed are the values of a certain population or sample in regards to the value of the mean.

In this example the variable is X: score obtained on a math test.

It's mean is μ= 52 and its standard deviation is σ= 10

To know how many standard deviations away is a value of X concerning the mean you have to first subtract the mean to the value of X, X - μ, and then you have to divide it by σ:

(X - μ)/ σ

If X=76

(76 - 52)/ 10= 2.4

The score obtained by Andrea is 2.4σ away from the mean.

I hope it helps!