What value of x makes the proportion below below correct? 7/8=x/64

Adam used 1072.4 gallons of water over the course of 7 days. how much water did adam use, on average, each day?

If f(x) = 2x + 8 and g(x) = x4, what is (gº)?

Carl's candies has determined that a candy bar measuring 3 inches long has a z-score of +1 and a candy bar measuring 3.75 inches long has a z-score of +2. what is the standard deviation of the length of candy bars produced at carl's candies?