The market price of pizzas in a college town increased recently, and the students in an economics class are debating the cause of the price increase....

The market price of pizzas in a college town increased recently, and the students in an economics class are debating the cause of the price increase. Some students suggest that the price increased because the price of dough, an important ingredient for making pizzas, has increased. Other students attribute the increase in the price of pizzas to a recent increase in the price of hamburgers at local burger joints.

Everyone agrees that the increase in the price of hamburgers was caused by a recent increase in the price of ground beef, which is not generally used in making pizzas. Assume that pizza parlors and burger joints are entirely separate entities—that is, there aren't places that serve both pizzas and hamburgers.

The first group of students thinks the increase in the price of pizzas is due to the fact that the price of dough, an important ingredient for making pizzas, has increased.