amandas average grade of 5 tests was 88 percent. her first four grades were 78 percent, 86 percent, 96 percent and 94 percent. what was grade of fifth test

Question

Find fifth tests grade

Answer 1

Hi Jamie,

 

Here's how you solve this:

 

We know Amanda's average for five tests was 88%.

 

This means that (Test1 + Test2 + Test3 + Test4 + Test5) ÷ 5 = 88.

We know the scores of her first 4 tests so we can plug those numbers in and solve.

 

(78 + 86 + 96 + 94 + Test5) ÷ 5 = 88

(354 + Test5) ÷ 5 = 88                                         Add

354 + Test5 = 440                                   Multiply both sides by 5

Test5 = 86                                           Subtract 354 from both sides

 

Her grade on the 5th test was 86%.