23) Total costs are $180,000 when 10,000 units are produced; of this amount, variable costs are $64,000. What are the total costs when 13,000 units are produced? 24) Portman Company's activity for the first three months of 2016 are as follows: Machine Hours Electrical Cost January 2,100 $4,800 February 2,600 $5,800 March 2,900 $6,400 Using the high-low method, how much is the cost per machine hour? a. $2.00 b. $3.00 c. $2.26 d. $1.78 25) Weatherspoon Company has a product with a selling price per unit of $200, the unit variable cost is $110, and the total monthly fixed costs are $300,000. How much is Weatherspoon's contribution margin per unit? a. $ 90 b. $110 c. $200 d. $300