Question

Sandy earned the following test scores (out of 100 points) on the first four tests inher business class: 87, 99, 94, and 92. Here mean test score is 93. What scorewould Sandy need to earn on the fifth test in order to raise her mean test score to94?

Answer 1

We have that Sandy earned the test scores:

87, 99, 94 and 92

We have that the mean at this point is 93, and we want to know the test score in a fifth test to obtain a mean of 94.

Then we have the system below:

`(87+99+94+92+x)(1)/(5)=94`

Where x represents the test score of the fifth test, so we solve it:

`x=(94*5)-87-99-94-92=98`

So we can conclude the correct answer is:

The score that Sandy would need to raise her mean test score to 94, is 98.