If the prices of all goods and services produced in the economy rose while the quantity of all goods and services stayed the same, which would rise?

Until recently, hamburgers at the city sports arena cost $4.70 each. the food concessionaire sold an average of 13 comma 000 hamburgers on game night. when the price was raised to $5.40, hamburger sales dropped off to an average of 6 comma 000 per night. (a) assuming a linear demand curve, find the price of a hamburger that will maximize the nightly hamburger revenue. (b) if the concessionaire had fixed costs of $1 comma 500 per night and the variable cost is $0.60 per hamburger, find the price of a hamburger that will maximize the nightly hamburger profit.