TPG Tax & Accounting is a full-service CPA firm located in Apache Junction, Arizona. Assume

that tax return services are classified into one of three categories: standard, complex, and full-service

(includes end-of-year bookkeeping with tax return preparation). Assume that TPG's fixed costs (rent, utilities, wages, and so forth) totaled $180,000 last year. Additional information from the prior year follows.

Standard Complex Full-Service Billing rate. . . . .. $125.00 $250.00 $150.00 Average variable costs . . . (45.00) (65.00) (50.00) Average contribution margin. . . $ 80.00 $185.00 $100.00 Number of returns prepared . . . . 1,000 200 800 Required a. Using sales dollar analysis, determine TPG's break-even dollar sales volume. b. Determine TPG's margin of safety in sales dollars. Hint: Use the weighted average billing rate. c. Prepare a profit-volume graph for Joe's Tax Service