SOLUTION: A student has scores of 87.25, 86.5, and 93.75 on his first three tests. He needs an average of at least 90 to earn a grade of A. What is the minimum score that the student needs o

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: A student has scores of 87.25, 86.5, and 93.75 on his first three tests. He needs an average of at least 90 to earn a grade of A. What is the minimum score that the student needs o      Log On


   

Question 211403: A student has scores of 87.25, 86.5, and 93.75 on his first three tests. He needs an average of at least 90 to earn a grade of A. What is the minimum score that the student needs on the fourth test to ensure a A?
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Let the fourth test score be x, so to get an average of at least 90 on the four test, then
%2887.25%2B86.5%2B93.75%2Bx%29%2F4+%3E=+90 Add the numeric scores then multiply both sides by 4.
267.5%2Bx+%3E=+360 Subtract 267.5 from both sides.
x+%3E=+92.5
The minimum score the student needs is 92.5