k got a 82%, 75%, and 74% on the first three tests. what grade does she need on the fourth test to Have an average of 80% on all four test
Let the grade on the fourth test be x.
To have an average of 80% on all four tests, the sum of all four test grades must be 80% x 4 = 320%.
Currently, the sum of the grades on the first three tests is 82% + 75% + 74% = 231%.
Therefore, the grade needed on the fourth test to have an average of 80% on all four tests is:
320% - 231% = 89%
So, she needs to score 89% on the fourth test to have an average of 80% on all four tests.