The Longreach Toy Factory has determined machine hours to be the cost driver of the company's Electricity costs . During the first six months of the year , the company incurred the following Electricity costs` I Louth Machine Hours Electricity Cost Jani 780 $82010) Feb 720 $8350 Mar $8950 APT 900 $9360 May 950 $9625 June 9 20 $9150 Using the high - low method , determine the cost formula that expresses the cost behaviour of the company's Electricity costs*