SOLUTION: Just looking for the formula to solve the following question: 36 students took a test that required a passing grade of 70. The mean of those who passed was 78. The mean of those

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Question 391174: Just looking for the formula to solve the following question:
36 students took a test that required a passing grade of 70. The mean of those who passed was 78. The mean of those who failed was 60. The total mean was 71. How many students failed.
I figured that 36 x 71 gives me the total number of points (2556). I know that 78 times some number less than 36 PLUS 60 times the rest of the 36 left over = 2556. I just can't figure out how to put this into a formula I can solve.
Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website!
36 students took a test that required a passing grade of 70.
The mean of those who passed was 78. The mean of those who failed was 60.
The total mean was 71. How many students failed.
:
Let x = those that failed
then
(36-x) = those that passed
:
= 71