The cost of each book is four dollars which means that on the y axis, you can’t have jumps of 1. If you look at graph B, you’ll notice that per each book bought (x axis) the cost shown on the y axis increases by four.
V ( cylinder ) = r² π h V ( cone ) = 1/3 r² π h A cone that fits exactly inside the cylinder has the volume: V ( cone ) = 1/3 V ( cylinder = 1/3 · 81 = 27 ft³
