Problem: A hardware store sold 200,000 units of a product at $5 per unit in November, and sold 205,000 units of the same product at $4.75 per unit in December. The store has 9 full-time employees and each employee works 48 hours per week. In the month of November, the store also had 4 part-time employees and each part-time employee worked 18 hours per week. In the month of December, the store also had 3 part-time employees and each part-time employee worked 20 hours per week. Assume that there are 4 work weeks in each month.
a. Find the labor productivity (expressed in sales dollars earned per labor-hour) for the month of November.
b. Find the labor productivity (expressed in sales dollars earned per labor-hour) for the month of December.
c. Find the percentage change in labor productivity from November to December.