Question

Ella’s test grades in her history class are 89, 94, 82, 84, and 98. What score must Ella make on her next test to have a mean test score of 90?

needed on the next test

Answer 1

You need 6 test scores to find the mean test score.
So we need to find the average of all the test scores.
That means we have to add all the test scores and divide by 6 because there are 6 test scores. Let’s think the the s
89+94+82+84+98+x/6=90
(X is the score that ella must have)
447+x/6=90
447+x=90x6
447+x=540
x=540-447
x=93. (Ella must have 93 test scores to have a mean test score of 90)