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

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.
$\frac{x}{5}=84 \\ x=84 \times 5 \\ x=420$
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.
$\frac{420+y}{6}=85 \\ 420+y=85 \times 6 \\ 420+y=510 \\ y=510-420 \\ y=90$

You need to score 90 points on the sixth test.

Answer 2

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