SOLUTION: A student has gotten the following grades on this test. 71,83,83,77. What is the minimum grade he must get on the last test in order to have an average of 81.

Algebra ->  Average -> SOLUTION: A student has gotten the following grades on this test. 71,83,83,77. What is the minimum grade he must get on the last test in order to have an average of 81.      Log On


   

Question 873519: A student has gotten the following grades on this test. 71,83,83,77. What is the minimum grade he must get on the last test in order to have an average of 81.
Answer by ben720(159) About Me  (Show Source):
You can put this solution on YOUR website!
Average(71,83,83,77,x)=81
%2871%2B83%2B83%2B77%2Bx%29%2F5=81
Add
%28344%2Bx%29%2F5=81
Multiply both sides by 5
344%2Bx=405
Subtract 344 from both sides
x=61

He would have to get a 61