piece-wise linear functions

Directions: Show all work, and answer each question that is asked. Explanations should be given in complete sentences. All graphs should be drawn accurately on this sheet, and be fully labeled.

A university department is planning to have a local company print custom shirts for them. The quoted price for creating and printing the shirts is as follows: The design and set-up fee is $75. The first 75 shirts are priced at $22.50 each. Any additional shirts are priced at $20.50 each. Find a formula for the function that represents the total cost of ordering n shirts from the company. How much would it cost to order 250 shirts?