an increase in the price of a product leads to * an increase in the marginal utility per dollar (mu?p) of that product, which leads to an increase in the quantity purchased. an increase in the marginal utility per dollar (mu/p) of that product, which leads to a decrease in the quantity purchased. a decrease in the marginal utility per dollar (mu/p) of that product, which leads to an increase in the quantity purchased. a decrease in the marginal utility per dollar (mu/p) of that product, which leads to a decrease in the quantity purchased.