Question

Ebony earned scores of 70, 78, 87, 96, and 82 on five math tests. Determine herscore on the sixth test if her average for the six tests was 83? Enter your answer as awhole number

Answer 1

We are given 5 test scores and an average which is 83 , in order to find average we add all scores and divide by the number of test taken .

as follows :

(T1+T2+T3+T4+T5+T6 )/ 6 = 83

(70 +78+87+96+82+T6)/6 = 83

(413+T6)/6 = 83...... (multiply both sides by 6)

413 +T6 = 83 x6

413 +T6 = 498 ......( collect like terms)

413 -413 +T6 = 498 -413

0 +T6 = 85

T6 = 85

This means that Test number 6, Ebony scores 85

we can prove this by adding it back to our equation on the first step and see if we will get 83 as an average:

(413 +85 )/6= 83