Question

You have a mean score of 84 after taking five 100-point tests. What do you need to score on the sixth 100-point test to have a mean score of 85?

**Highschool Algebra 1 Question**

Answer 1

Answer: the mean of n numbers is the sum of the numbers divided by n.

You have a mean score of 84 after taking 5 tests. Let x be the sum of scores.

You scored a total of 420 points on five tests.

You need to have a mean score of 85 after taking 6 tests. Let y be the score you need to obtain. Your total score on 6 tests is 420+y.

You need to score 90 points on the sixth test

Answer 2

The mean of n numbers is the sum of the numbers divided by n.

You have a mean score of 84 after taking 5 tests. Let x be the sum of scores.

`(x)/(5)=84 \\ x=84 * 5 \\ x=420`
You scored a total of 420 points on five tests.

You need to have a mean score of 85 after taking 6 tests. Let y be the score you need to obtain. Your total score on 6 tests is 420+y.

`(420+y)/(6)=85 \\ 420+y=85 * 6 \\ 420+y=510 \\ y=510-420 \\ y=90`

You need to score 90 points on the sixth test.