#### Answer

$15

#### Work Step by Step

Looking at the graph, the price per bag when you are buying 1500 bags is 1 cents per bag so you using the function C(b)=b, we can deduce that when b=1500, C(b)=1500 cents which is equal 15 dollars since 100 cents in one dollar.
Therefore, it will cost 15 dollars to buy 1500 bags.