SOLUTION: Helping my son, 7th grade. We need help please. Q- average for five quizzes is 86. To have an average of 88 or more for six quizzes, what is the lowest score to get on the six

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Question 281164: Helping my son, 7th grade. We need help please.
Q- average for five quizzes is 86. To have an average of 88 or more for six quizzes, what is the lowest score to get on the sixth quiz?
Thanks.

Found 2 solutions by richwmiller, josmiceli:
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
(5*86+x)/6=88
Good luck you need at least 98
think of it this way
you need at least 88 plus you have to make up 2 points for the last 5 quizzes. So you need 5*2+88=98

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let x = lowest score to get on 6th quiz
The average is:
(sum of scores on quizzes)/(number of quizzes) = average grade
For the 1st 5 quizzes, the average is 86
(Sum of scores on 5 quizzes)/5 = 86
Sum of scores on 5 quizzes = 5*86
Sum of scores on 5 quizzes = 430
and, after taking the 6th quiz:
%28430+%2B+x%29%2F6+=+88
Multiply both sides by 6
430+%2B+x+=+6%2A88
430+%2B+x+=+528
x+=+98
Must get at least a 98 to average 88 for 6 quizzes
check:
%28430+%2B+98%29%2F6+=+88
528%2F6+=+88
88+=+88
OK