Emerald Electronics manufactures basic and advanced model smartphones. The basic model is sold at $300 each, and the advanced model is sold at $600 each. The variable cost of making the basic model is $200 each. It costs an extra $150 to make the advanced model. It takes 25 labor hours to make 100 basic smartphones and 35 labor hours to make 100 advanced smartphones. There are 4,500 hours of labor time available for production each week. The maximum weekly sales for the basic and advanced smartphones are 1,000 and 500 units, respectively. Fixed production costs total $1,200,000 per year. All selling costs are fixed.

Required: (a) Calculate the optimal production level in number of units for each product. (b) Prepare the ledgers for both types of smartphones showing all necessary entries. (c) Compute the total contribution margin for the company.