SOLUTION: After five exams, Andrew has a mean mark of 70. What mark must he get in the next exam to raise his average to 72?

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Question 992312: After five exams, Andrew has a mean mark of 70.
What mark must he get in the next exam to raise
his average to 72?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
After five exams, Andrew has a mean mark of 70.
What mark must he get in the next exam to raise his average to 72?
:
let x = the mark of the 6th exam
%285%2870%29%2Bx%29%2F6 = 72
%28350%2Bx%29%2F6 = 72
multiply both sides by 6
350 + x = 6(72)
subtract 350 from both sides
x = 432 - 350
x = 82 is the grade must get to raise his average to 72