SOLUTION: Masha’s grades in Mathematics for the first three quarters are 78, 89, and 97, respectively. If she wants to have an average grade of at least 90, what must she get for her 4th g

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Question 1193459: Masha’s grades in Mathematics for the first three quarters are 78, 89, and 97, respectively. If she wants to have an average grade of at least 90, what must she get for her 4th grading grade (x)?
Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
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Masha’s grades in Mathematics for the first three quarters are 78, 89, and 97, respectively.
If she wants to have an average grade of at least 90, what must she get for her 4th grading grade (x)?
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She wants

    %2878+%2B+89+%2B+97+%2B+x%29%2F4 >= 90.


Multiply both sides of this inequality by 4 and then simplify


    78 + 89 + 97 + x >= 4*90

                   x > = 360 - 78 - 89 - 97

                   x >= 96.


ANSWER.  She must have x at least 96.

Solved.

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