Question

Anxious Billy Bob pulled out his math recording sheet and saw the following scores
54,62,65,68,70,70,78,82,84
A. He want to calculate his average.Which measure of center is the average?compute it ?

I have this :The measure of center is the average, mean
633/9=70.33=about 70%

B.He has one more exam left and he would like to end the marking period with at least a 72 average .What would his last exam score have to be.
?????????

Answer 1

Your mean is correct

to get a mean of 72, let the extra score be x
and he now has 10 scores to average

(633 + x)/10 = 72
633 + x = 720
x = 720-633 = 87

he needs an 87

or, think of it this way.
to have an average of 72 on 10 tests, he needs a total score of 720
so far he has 633, so he needs 87 more

PS. I did not check your sum of 633, I assume it is correct.