SOLUTION: alan's scores on his first three exams are 85, 90, and 61. what must alan score on his next exam to average 77 for all four exams?

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Question 1082887: alan's scores on his first three exams are 85, 90, and 61. what must alan score on his next exam to average 77 for all four exams?
Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!
Let the fourth exam have score x.

To average numbers we add them and divide by the number of
numbers.

So we add all four together and divide by 4.  Then we set that 
equal to 77 

%2885%2B90%2B61%2Bx%29%2F4%22%22=%22%2277

Now solve for x.

Begin by multiplying both sides by 4 to get rid of the 
denominator of 4.

You finish.

Edwin