SOLUTION: Mike needs at least a 75% average to pass his math course. The class contains 5 exams that are equally weighted. If he scored a 64%, 86%, 71%, and 90% on the first 4 tests, what

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Question 835403: Mike needs at least a 75% average to pass his math course. The class contains 5 exams that are equally weighted. If he scored a 64%, 86%, 71%, and 90% on the first 4 tests, what score does he need on the final test to earn at least a 75% in the class
Answer by LinnW(1048) About Me  (Show Source):
You can put this solution on YOUR website!
First find the grade on the test that will produce an average
grade of 75.
Set x = the grade on the 5th test.
%2864+%2B+86+%2B+71+%2B+90+%2B+x%29%2F5=75
%28311+%2B+x%29%2F5=75
multiply each side by 5
311+%2B+x=75%2A5
311+%2B+x=375
add -311 to each side
x=375-311
x=64
So a grade of 64 produces an average of 75
and a grade of 64 or above will produce
an average greater than or equal to 75