Question 285148
If a student has grade of 90,78, and 82 on the first three math test, what steps would you take to find the grade the student must get on her fourth math test to have an average of 90?
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Let 4th test grade be "x".
Equation:
(90+78+82+x)/4 = 90
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(250+x) = 360
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x = 110
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Cheers,
Stan H.