To solve this problem step-by-step, we need to determine the Marginal Revenue Product (MRP) of the third worker. MRP is calculated as the change in total revenue (TR) that results from hiring one more worker. The total revenue is the product of the output and the product price.
1. Identify the output with two and three workers:
- When there are 2 workers, the output is 45 (from Exhibit 11-2).
- When there are 3 workers, the output is 80 (from Exhibit 11-2).
2. Calculate the Marginal Product (MP) of the third worker:
- MP is the additional output generated by the third worker:
[tex]\[
MP = \text{Output with 3 workers} - \text{Output with 2 workers} = 80 - 45 = 35
\][/tex]
3. Calculate the total revenue change due to the third worker:
- The product price is fixed at [tex]\( \$5 \)[/tex] per unit.
- Total revenue generated by the third worker can be calculated as:
[tex]\[
\text{MRP} = \text{Marginal Product} \times \text{Product Price} = 35 \times 5 = 175
\][/tex]
From this calculation, we find that the MRP of the third worker is:
[tex]\[
\boxed{175}
\][/tex]
Thus, the correct answer is:
b. [tex]\(\$175\)[/tex].
