The following 6 months of data were collected on electricity cost and the number of machine hours in a factory. Electricity Machine Month cost hours June $25,160 4,730 July 25,262 4,676 August 27,250 5,120 September 27,602 5,010 October 27,124 5,286 November 26,680 5,090 Calculate the slope of the cost line using the high-low method. Enter your answer with at least 2 decimal places.