Answer parts (A) and (B) in Example 7 for fixed costs of $250 per day and total costs of $3,450 per day at an output of 80 skateboards per day.

Data from Example 7

The management of a company that manufactures skateboards has fixed costs (costs at 0 output) of $300 per day and total costs of $4,300 per day at an output of 100 skateboards per day. Assume that cost C is linearly related to output x.

Find the slope of the line joining the points associated with outputs of 0 and 100, that is, the line passing through (0, 300) and (100, 4,300).

Find an equation of the line relating output to cost. Write the final answer in the form C = mx + b.

Graph the cost equation from part (B) for 0 ≤ x ≤ 20