SOLUTION: Heather received grades of 80, 75, and 86 on three algebra tests. What must her grade be on the next test if her average for the four tests is to be at least 82? Thank You!!! :)

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Question 56013This question is from textbook Algebra 1
: Heather received grades of 80, 75, and 86 on three algebra tests. What must her grade be on the next test if her average for the four tests is to be at least 82?
Thank You!!! :) This question is from textbook Algebra 1

Answer by Lacey020991(49) About Me  (Show Source):
You can put this solution on YOUR website!
You would work this almost just as if you had the fourth test grade.
The test grades were 80, 75, 86, & x
They have to be atleast an 82.
.
%2880%2B75%2B86%2Bx%29%2F4=82
To get rid of the fraction multiply each side by 4. The fours on the left side would cancel out
4%2880%2B75%2B86%2Bx%29%2F4=82%2A4
80%2B75%2B86%2Bx=328
.
Add up the test grades
241 + x = 328
.
then subtract 241 from each side
x = 87
So she would have to make atleast a 87 on the next to to have an average of atleast 82.