SOLUTION: A friend has a 85% average before the final exam for a course. That score includes everything but the final, which counts for 15% of the course grade. What is the best course gr

Question 1200683: A friend has a 85% average before the final exam for a course. That score includes everything but the final, which counts for 15% of the course grade.
What is the best course grade your friend can earn?
%
What is the minimum score would your friend would need on the final to earn a 75% for the course?
Found 3 solutions by Theo, Alan3354, ikleyn:
Answer by Theo(13342)   (Show Source): You can put this solution on YOUR website!
85 is equal to 85% of the grade.
the final is equal to 15% of the grade.
the best he could do on the final is 100.
.85 * 85 + .15 * 100 = 87.25.
that's the best grade he can get, if the best grade he can get on a test is 100.

to earn a 75 for the course, you get:
.85 * 85 + .15 * x = 75
subtract .85 * 85 from both sides of the equation to get:
.15 * x = 75 - .85 * 85
divide both sides of the equation by .15 to get:
x = (75 - .85 * 85) / .15
solve for x to get:
x = 18.333333...... = 18 + 1/3 = 55/3.
.85 * 85 + .15 * 55/3 = 75.

those are the solutions that i believe you are looking for.

Answer by Alan3354(69443)   (Show Source): You can put this solution on YOUR website!
A friend has a 85% average before the final exam for a course. That score includes everything but the final, which counts for 15% of the course grade.
What is the best course grade your friend can earn?
If he get 100% on the final:
Avg = (85*85 + 15*100)/100 = 87.25%
---------------
What is the minimum score would your friend need on the final to earn a 75% for the course?
---
85*85 + 15*S = 7500
S = 15

Answer by ikleyn(52803)   (Show Source): You can put this solution on YOUR website!
.
A friend has a 85% average before the final exam for a course. That score includes everything
but the final, which counts for 15% of the course grade.
(a) What is the best course grade your friend can earn?
%
(b) What is the minimum score would your friend would need on the final to earn a 75% for the course?
~~~~~~~~~~~~~~~~~~~~

            In this my post, I will solve/answer part (b), ONLY.

That 85% average, which he just have, go to the course grade (= contribute) with the weight of (1-0.15) = 0.85. Those percents of the final that he will earn in the future, go to the course grade (= contribute) with the weight of 0.15. So, for question (b), you should solve this inequality 0.85*0.85 + 0.15x >= 0.75. From this inequality, find x x >= = 0.18333... ANSWER to question (b)

Solved.

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