Calculator Print Item Marigold Company makes furniture. The company controller wanted to calculate the fixed and variable costs associated with electricity use in the factory. Data for the past four months were collected as follows: Electricity Month January February March urs $8,000 7,200 7,500 8,200 650 580 690 Coefficients shown by a regression program are as follows: 3,500 7.25 X Variable 1 Using the results of regression, calculate the variable rate of the electricity cost. a. $5.75per machine hour b.$7.25 per machine hour C. $6.39 per machine hour d. None of these choices are correct