Question 4 [10 marks] The following six months of data were collected on electricity cost and the number of machine hours in a factory. Electricity Machine Month cost hours June R25,160 4,500 July 26,170 4,810 August 27,250 5,120 September 26,680 5,010 October 27,950 5,430 November 27,500 5,190 Required: 1. Using the high-low method compute the variable rate for the electricity cost. (4 marks) 2. Using the high-low method compute the fixed cost of electricity. (3 marks) 3. Estimate the total electricity cost to be incurred in December if 5,300 machine hours are incurred