In order to solve this, you have to take the number of copies of the Prisoner of Azkaban and divide it by the number of copies of the Sorcerer's Stone:
13.2÷20=0.66
To get this into a percentage, multiply the 0.66 by 100, and get 66%, meaning that The Prisoner of Azkaban was sold only 66% as much as The Sorcerer's Stone.
Log (5) + log (3) = log (15)
The volume of the pyramid is 432ft3.
Its b= -0.2 or b= 1/-5 whichever one works best
