Suppose total cost in dollars from the production of x printers is given by
C(x) = 0.0001x3 + 0.005x2 + 28x + 3000
Find the average rate of change of total cost when production changes
(a) From 100 to 300 printers.
(b) From 300 to 600 printers.
(c) Interpret the results from parts (a) and (b).