65.6k views
2 votes
Kane's average on his first four English quizzes are 91, 94, 78, and 90. What must Kane's score be on his

5ch English quiz if he wants an 88 average?

User Nwalton
by
3.8k points

2 Answers

2 votes

Answer:

87

Explanation:

[] First we need to set up an equation


(91 + 94 + 78 + 90 + x)/(5) = 88

[] What does it mean? We want all of his scores plus the 5th test score (x) to equal an average of 88 so we must find the average of all of his test scores.

[] Now to solve!

First, let's multipy everything by 5 to remove the fraction.

91 + 94 + 78 + 90 + x = 440

Then, simplify

353 + x = 440

Now subtract the 353 from both sides

x = 87

Which results with our answer, he needs to get an 87!

Hope this helps, have a nice day :)

User Kenitech
by
3.7k points
5 votes

Answer:

The 5th score has to be 87.

Explanation:

Equation

(91 + 94 + 78 + 90 + x)/5 = 88 Multiply both sides by 5

91 + 94 + 78 + 90 + x = 88*5 Combine like terms on both sides.

353 + x = 440 Subtract 353 from both sides.

x = 440 - 353

x = 87

User Kaiting Chen
by
4.2k points