Fast Company's activity for the first six months of the year appear below:

Machine Hours Electrical Cost

January 4,000 $3,120

February 6,000 $4,460

March 4,800 $3,500

April 5,800 $5,040

May 3,600 $2,900

June 4,200 $3,200

Required: Using the high-low method of analysis, estimate the variable electrical cost per machine hour.

Select one:

a. $0.25

b. $1.00

c. $0.65

d. $0.50