1. Tilly Company had the following cost and volume data for the first four months of the year.

January: Cost of $52,500; volume of 9,000 units

February: Cost of $40,000; volume of 6,500 units

March: Cost of $70,000; volume of 14,000 units

April: Cost of $60,000; volume of 11,000 units

Using the scattergraph method, which ONE of the following is the BEST estimate of the variable cost per unit?

a. $25.00 per unit

b. $15.00 per unit

c. $4.00 per unit

d. $35.00 per unit

e. $10.00 per unit

f. $8.00 per unit