Katie must take five exams in a math

Zane Decker

Zane Decker

Answered question

2022-04-16

Katie must take five exams in a math class. If her scores on the first four exams are 76, 74, 90, and 88, what score must Katie get on the fifth exam for her overall mean to be at least 80?

Answer & Explanation

phoenixtreeaung

phoenixtreeaung

Beginner2022-04-17Added 19 answers

To get the overall mean, we should add all of the scores of her five exams and divide the sum by 5. This is represented in the following equation. "x" represents the fifth exam's score.
(76+74+90+88+x)/5=80
Multiply both sides of the equation by 5 to get...
76+74+90+88+x=400.
Add all of the four given exam scores.
328+x=400
Then, subtract 328 from both sides of the equation to get...
x=72
Result:
Her fifth exam's score must be 72 for her overall mean to be at least 80.
Wrastirtyzp9w

Wrastirtyzp9w

Beginner2022-04-18Added 10 answers

Suppose that a score of x marks in the fifth exam yields Katie the
desired mean.
Then, the Mean score of all the tests =76+74+90+88+x5, and, as
this is reqd. to be at least 80, we have,
76+74+90+88+x580
328+x580
328+x5×80=400
x400328=72
So, in the fifth test, Katie has to score at least 72 for the purpose.

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