Solve the Problem $c ( x ) = x ^ { 3 } - 22 x ^ { 2 } + 20,000 x$

Multiple Choice

Solve the problem.
-Suppose $c ( x ) = x ^ { 3 } - 22 x ^ { 2 } + 20,000 x$ is the cost of manufacturing $x$ items. Find a production level that will minimize the average cost of making $x$ items.

A) 13 items
B) 11 items
C) 10 items
D) 12 items