Question

Justin earned scores of 85, 92, and 95 on his science tests. What does he need to earn on his next science test to have an average (arithmetic mean) of 93%?

Answer 1

Answer:

85+92+95+100=372=93%

Answer 2

Given,

The score of Justin in his previous science tests are = 85,92 and 95.

To find,

The score of Justin in his next science exam to score an average of 93%.

Solution,

First of all, we will assume that each of the exams has a full marks of 100.

Let, the marks in the fourth exam = x

( Assume, x as a variable to do the further mathematical calculations.)

Total obtained number in the four exams = (85+92+95+x) = 272+x

Total marks of the four exams = (100×4) = 400

Average marks = (272+x)/4

Now, according to the data mentioned in the question,

(272+x)/4 = 93

272+x = 372

x = 100

Hence, he needs to score 100 in his fourth exam.