Answer:
The value of the marginal product of the last worker hired is $20
The marginal product of the last worker hired is 4 sandwiches per hour
Please kindly note the difference between the terms, value of marginal product and the term marginal product
Explanation:
Since the uncle is trying to maximize profit, then he will hire workers up to a point where the wages of the workers equals their marginal product value
Now, from the question, the value of the wages is $20 per hour, this also means that their marginal product too will be $20 per hour
This automatically means that the value of the marginal product of the last worker hired is also $20
Mathematically;
Value of marginal product = Marginal product * price
Thus, marginal product = value of marginal product/ price
= $20/$5 = 4
This means that the new worker hired marginal product is 4 sandwiches per hour