JR Landscape Services pays \(\$ 5,000\) per month for equipment rental. In addition, variable charges incurred average \(\$ 400\) for each customer landscaping project.

a. Determine the total cost and the cost per customer (rounded to the nearest whole dollar) if JR expects to complete the following number of projects for the month of June:

1. 100 2. 300 3. 500

b. JR wants to earn a margin (excluding any other direct costs) on landscaping projects of \(\$ 35,000\) during June. If 300 projects are completed, what landscaping fee should be charged per project?

c. If that fee is charged and 350 projects are completed in June, what is the total margin in June?