Answer:
Melissa
Step-by-step explanation:
Melissa earned $390 while mike only made $230
You add all the percentages up and it will give you 64. take 64 and put it over 100 because percentages as a fraction will always be the amount over a 100.
so its 64/100 multiply by 4000/1. 64*4000= 256000 over 100. 256000 divided by 100 = 2560
$2560
I set this up as an inequality,

. If you take the cubed root of 800, you get the lower bound of the side length, which is 9.2. Then I just worked my way up until I hit the first number that put me over a volume of 800. That number is 9.29, because 9.28 cubed is 799.1 (not high enough) and 9.29 cubed is 801.8. Therefore, the bounds of the sides exist within a conjunction:

. That's the best I could come up with to help on that one. Wasn't sure if there was another method you were taught at school. I just used common sense more than any rule.