SOLUTION: On her last three quizzes Elise scored 84 96 and 88. What grade must she get on her next quiz to have an average of 90 for all for quizzes ? Thank you ! (:
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-> SOLUTION: On her last three quizzes Elise scored 84 96 and 88. What grade must she get on her next quiz to have an average of 90 for all for quizzes ? Thank you ! (:
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Question 526739: On her last three quizzes Elise scored 84 96 and 88. What grade must she get on her next quiz to have an average of 90 for all for quizzes ? Thank you ! (: Answer by Maths68(1474) (Show Source):
Average = some of quantities / number of quantities
90=(84+96+88+x)/4
90=(268+x)/4
Multiply by 4 both sides
90*4=4*(268+x)/4
360=268+x
360-268=x
92=x
x=92
Elise must score 92 to get an average of 90
Check
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Average = some of quantities / number of quantities
Average = (84+96+88+92)/4
Average = 360/4
Average = 90
