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Math

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John has scores of 88,73,90,85,93 on five math quizzes. What scores must john earn on the next math quiz to have a mean quiz score of exactly 88?

  • Math -

    The mean means:

    Add all numbers and then divide how many numbers there are

    First Step:

    88 + 73 + 90 + 85 + 93 = 429

    Second Step:

    429 / 5 = 85.8 <--- that is the mean of what you got.

    However, the question asks you for what future grade you must make on the next test to average an 88% with those current grades. So this will tell us that we have to make at least in the 90's.

    So we try 99%

    88 + 73 + 90 + 85 + 93 + '99' = 528

    then again we must divide by amount of numbers. Which there are 6 now, instead of 5.

    528 / 6 = 88

    So, in order for a student to receive an average of an 88%, they must make a 99% on the next test.


    Cheers!

  • Math -

    Johns next quizz will be 6-th.
    If He want 88 points in tis case must be:

    (88+73+90+85+93+x)/6=88

    88+73+90+85+93+x=88*6

    429+x=528

    x=528-429

    x=99

    (88+73+90+85+93+99)/6= 528/6 = 88

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