Broccoil cost 1.50 per pound at the grocery store. how much money does 64 ounces od broccoli cost before tax?

The conversion factor of ounces to pound is 16 ounces per 1 pound. The ratio and proportion concept is used here. The ratio of the price of broccoli per pound should be the same with that of the price of 64 ounces. 
                     ($1.50 / pound) x (1 pound/ 16 ounces) = (P / 64 ounces)
The value of P in the equation is 6. Thus, the price of 64 ounces of broccoli should be $6.