In MMW class, a student’s quiz scores are 89, 92, 82, and 77. What score does the student need on the fifth quiz
to have a mean quiz score of 85? All the quizzes have equal weights. Round your answer to the nearest whole
number.
Quiz score is 89%, 92%, 82% and 77%
We want to find score of "5^t" quiz so that the mean score= 85%
Assume that fifth quiz have score X
"Mean= \\frac{Sum \\; of \\; all \\; quiz \\; scores }{Number \\; of\\; quizes} \\\\\n\n0.85=\\frac{0.89 + 0.92 + 0.82 + 0.77 + X}{5} \\\\\n\n0.85=\\frac{3.4 +X}{5} \\\\\n\n4.25=3.4 +X \\\\\n\nX=4.25 -3.4 \\\\\n\nX=0.85 \\\\\n\nX=85\\; \\%"
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