SOLUTION: Can you please help me with this question? This question is from Algebra II, A Beka Book. Sarah has an average of 92.5 for her 3 science tests. What does she need to make on the

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Question 86026: Can you please help me with this question? This question is from Algebra II, A Beka Book.
Sarah has an average of 92.5 for her 3 science tests. What does she need to make on the 4th test to get a 94% average?
Thank you so much for your help.
Found 2 solutions by tutor_paul, bucky:
Answer by tutor_paul(519) (Show Source):
You can put this solution on YOUR website!
If you consider her first 3 tests, you can write the following equation, where x,y, and z are her test scores:

Equation #1:
Now, after she takes her 4th test to achieve the 94 average, (call that score 'w'), you can write:
Equation #2:
Now, substitute the value of (x+y+z) from Equation #1 into Equation #2:

And solve for w...

Good Luck,
tutor_paul@yahoo.com

Answer by bucky(2189) (Show Source):
You can put this solution on YOUR website!
Let's presume that Sarah takes tests that have a maximum score of 100 points. So her 92.5
average means that on the three tests she took she scored an average of 92.5 points
each time.
.
Since Sarah has averaged 92.5 on three tests, on these three tests she has gotten a total
of 92.5 times 3 or 277.5 points.
.
If she is to average 94 points on 4 tests she will need 94 times 4 = 376 points.
.
Therefore, on the next test she will have to score enough points to take her total score from
277.5 points to 376 points.
.
Find the answer by subtracting 277.5 from 376 and you find that she will need 98.5 points
out of 100 (or 98.5 percent) on her next exam.
.
Hope this helps you to understand the problem.