What is meant by a products contribution margin ratio and how is this ratio useful in the planning of business operations?

Tony’s Textile Company sells shirts for men and boys. The average selling price and variable cost for each product are as follows:
Mens Boys
Selling Price $28.80 Selling Price $24.00
Variable Cost $20.40 Variable Cost $16.80
Fixed costs are $38,400.
Required:
What is the breakeven point in units for each type of shirt, assuming the sales mix is 2:1 in favor of mens shirts? (1.5 marks)
What is the operating income, assuming the sales mix is 2:1 in favor of mens shirts, and sales total 9,000 shirts? (1.5 marks)
What is meant by a product’s contribution margin ratio and how is this ratio useful in the planning of business operations? (2 marks)
Question 4 (5 marks)
Byron Sports is a manufacturer of sportswear. It produces all of its products in one department
using a process costing system.
The information for the current month is as follows:
Beginning work in process (30% complete as to conversion cost) 12,000 units
Units started 90,000 units
Units completed and transferred out ?
Ending work in process (70% complete as to conversion) 8,000 units
Costs:
Beginning work-in-process direct materials $28,800
Beginning work-in-process conversion $5,040
Direct materials added during month $216,000
Conversion costs incurred during the month $139,200
Direct materials are added at the beginning of the process. Conversion costs are incurred uniformly
throughout the production process. Costing is handled on a FIFO basis
Required:
a. Prepare a production cost worksheet using 5 steps approach. (3 marks)
b.Under what conditions would a process costing system be more appropriate than a job order costing system? Explain. (2 marks)