Question

6. Emily wants to earn a 90% in her math class. She has one test left to

take. On the first 4 tests she made a 92%, 87%, 95%, 98%. What must she
score on her 5th test to get the 90% she wants?

Answer 1

78%

Explanation:

You want to know the grade Emily needs on her 5th test to earn an average score of 90%, given her first 4 tests had grades 92%, 87%, 95%, 98%.

Average

Emily's average grade is the sum of the test scores divided by their number. She wants that to be 90:

(92 +87 +95 +98 +x)/5 = 90

x + 372 = 450 . . . . . . . . . multiply by 5

x = 78 . . . . . . . . . . . . . subtract 372

Emily must score 78% on her 5th test to get the grade she wants.

<95141404393>