SOLUTION: The average grade of Folly in his 6 subjects is 83.45. What grade must he have in his 7th subject so that he will have the average of 85? Thank you
Question 1121565: The average grade of Folly in his 6 subjects is 83.45. What grade must he have in his 7th subject so that he will have the average of 85? Thank you Found 4 solutions by Stitch, ankor@dixie-net.com, Alan3354, MathTherapy:Answer by Stitch(470) (Show Source): You can put this solution on YOUR website! Let C = The current grade sum of his previous 6 tests.
Let G = Be the grade needed on the 7th test
We can now write two equations.
Equation 1:
Equation 2:
Lets start by solving equation 1 for C:
Multiply both sides by 6
Simplify
Now plug 500.7 into equation 2 for C
Equation 2:
Multiply both sides by 7
Simplify
Subtract 500.7 from both sides.
Folly will have to get a score of 94.3 on the next test. Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website! The average grade of Folly in his 6 subjects is 83.45.
Find the total grade for these 6 subjects
6 * 83.45 = 500.7
What grade must he have in his 7th subject so that he will have the average of 85?
let x = the grade of the 7th subject = 85
500.7 + x = 85 * 7
x = 595 - 500.7
x = 94.3
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website! The average grade of Folly in his 6 subjects is 83.45. What grade must he have in his 7th subject so that he will have the average of 85?
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(6*83.45 + G)/7 = 7*85