Andy has grades of 84,65,76 on three maths tests . What grade must he obtain on the next test to have anaverage of exactly 80 for the four tests ? How to solve it ?
Marks: 84 65 76
But Avg needed in 4 tests is 80
Let the mark be in 4th test be x
Average=Totalmarks/no of tests
80=76+65+84+x/4
225+x=80*4
x=320-225
=95 marks
Hope this helps Thumbs Upp plss