SOLUTION: Please help me solve this problem. Jamyce has received grades of 89, 92, and 85 on 3 tests. What grade must she get on the next test in order to have an average of 90? 89+92+

Algebra ->  Average -> SOLUTION: Please help me solve this problem. Jamyce has received grades of 89, 92, and 85 on 3 tests. What grade must she get on the next test in order to have an average of 90? 89+92+      Log On


   

Question 552183: Please help me solve this problem.
Jamyce has received grades of 89, 92, and 85 on 3 tests. What grade must she get on the next test in order to have an average of 90?
89+92+85= 266
266/3 = 88.6666...
What is the next step?

Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
Let x = score on fourth test
then
(89+92+85+x)/4 = 90
(266+x)/4 = 90
(266+x) = 360
x = 360-266
x = 94