SOLUTION: Suppose that the mean score of 28 students (in a class of 30 students) in a quiz is 28. What should be the mean of the remaining 2 students in the class in order that the class mea

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Question 1193389: Suppose that the mean score of 28 students (in a class of 30 students) in a quiz is 28. What should be the mean of the remaining 2 students in the class in order that the class mean is 30?
Answer by ikleyn(52809) About Me  (Show Source):
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Suppose that the mean score of 28 students (in a class of 30 students) in a quiz is 28.
What should be the mean of the remaining 2 students in the class in order that the class mean is 30?
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Let the mean of the remaining 2 students in the class be x.


Then the total scores of the 30 students is  28*28 + 2x and the average of the 30 students is  %2828%2A28%2B2x%29%2F30.


So an equation to find x is this

    %2828%2A28%2B2x%29%2F30 = 30.


Simplify and find x

    28*28 + 2x = 30*30

      784 + 2x =   900

            2x = 900 - 784

            2x = 116

             x = 116/2 = 58.


ANSWER.  The mean score of the remaining 2 students in the class should be 58.

Solved.