6.1. A firm uses the inputs of fertilizer, labor, and hothouses to produce roses. Suppose that when the quantity of labor and hothouses is fixed, the relationship between the quantity of fertilizer and the number of roses produced is given by the following table:

Tons of Number of Tons of Number of Fertilizer Roses Fertilizer Roses per Month per Month per Month per Month 0 0 5 2500 1 500 6 2600 2 1000 7 2500 3 1700 8 2000 4 2200

a) What is the average product of fertilizer when 4 tons are used?

b) What is the marginal product of the sixth ton of fertilizer?

c) Does this total product function exhibit diminishing marginal returns? If so, over what quantities of fertilizer do they occur?

d) Does this total product function exhibit diminishing total returns? If so, over what quantities of fertilizer do they occur?