Using the high-low method, estimate the cost formula for billing expense. Round off both the fixed cost and the variable cost per thousand units sold to the nearest whole dollar

Question 1: Contribution format income statement and High-Low Method The accounting department of Archer Company, a merchandising company, has prepared the following analysis: Cost Formula Cost $ 56 per unit Cost of goods sold 12% of sales Sales commissions Advertising expense $ 300,000 per month Administrative salaries $ 160,000 per month Billing expense ? Depreciation expense $ 62,000 per month The accounting department feels that billing expense is a mixed cost, containing both fixed and variable cost elements. The billing expenses and sales in units over the last several months follow: Units Sold Billing Expense (thousands) January 9 $ 30,000 February 11 $ 33,000 March 14 $ 36,000 April 17 $ 42,000 May 15 $ 39,000 June 12 $ 35,000 The accounting department now plans to develop a cost formula for billing expense so that a contribution format income statement can be prepared for management's use