19 The following data pertains to activity and utility costs for two recent years: Activity level in units .. Utilities cost observed... Year 2 Year 1 10,000 6,000 S12,000 $9,000 Using the high-low method, the cost formula for utilities is O $2,000 plus $1.50 per unit O $4.000 plus $1.20 per unit O $3,000 plus $3.00 per unit O $4.500 plus $0.75 per unit