Answer:
a. 14.13 Hamburger per week b. 13.78 Hamburger per week
Explanation:
a. First of all we can convert all the items on the menu to a same unit.
1 Cheese Burger = 1.29 Hamburger
1 Chicken Sandwich = 0.8 Hamburger
So in the first week total output of the restaurant is
Output = 700 Hamburger + 900 Cheeseburger + 500 Chicken Sandwich
or
Output = 700 Hamburger + 900*1.29 Hamburger + 500*0.8 Hamburger
Output = 2261 Hamburger
And as there are 4 workers so total input is
Input = 4*40 = 160 hours
The productivity is given by
Productivity = Output/Input
So
Productivity = 2261 Hamburgers/160 Hours
Productivity = 14.13 Hamburger per week
b. If the restaurant sold 720 of each sandwich, then total output would be given by
Output = 720 Hamburger + 720 Cheeseburger + 720 Chicken Sandwich
Output = 720 Hamburger + 720*1.29 Hamburger + 720*0.8 Hamburger
Output = 2204.8 Hamburger
So the productivity would have been
Productivity = 2204.8 Hamburgers/160 Hours
Productivity = 13.78 Hamburger per week
Which would have been lower as that of in the first case.