SOLUTION: Julia received an average of 88% after completing four Maths exams. If he aims to increase his average by 2%, find what her next score should be.
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Question 1137453: Julia received an average of 88% after completing four Maths exams. If he aims to increase his average by 2%, find what her next score should be.
Or here is a way you can work problems like this involving averages of numbers that are all close together.
Her current average after 4 tests is 88; she wants an average of 90 after 5 tests.
On average, her 4 tests are each 2 points below the average she wants after 5 tests. That means her current point total is 8 points below what she needs to get the average she wants. And that means the 5th test has to be 8 points above the average she wants.
So the score she needs to get the 90 average for the 5 tests is 90+8 = 98.
After completing 4 Math exams, Julia has 88*4 = 352 scores, in all.
Let the next score be " x ".
Then her sum after 5 exams will be 352 + x.
She wants = 88 + 2 = 90.
Hence, x = 90*5 - 352 = 98.
ANSWER. Julia should get 98 in the 5-th exam.
