The assistant is unsure how to classify the utilities costs in the Radiology Department because these costs do not exhibit either strictly variable or fixed cost behavior. Utilities costs are very high in the department due to a CAT scanner that draws a large amount of power and is kept running at all times. The scanner cant be turned off due to the long warm-up period required for its use. When the scanner is used to scan a patient, it consumes an additional burst of power. The assistant has accumulated the following data on utilities costs and use of the scanner since the first of the year.

Month	Number of Scans	Utilities Cost
January	90	$5,100
February	70	$4,100
March	60	$4,000
April	80	$4,600
May	110	$6,400
June	100	$6,000
July	50	$4,400
August	40	$3,600
September	30	$3,800
October	20	$1,900

The chief administrator has informed her assistant that the utilities cost is probably a mixed cost that will have to be broken down into its variable and fixed cost elements by use of a scattergraph. The assistant feels, however, that if an analysis of this type is necessary, then the high-low method should be used, since it is easier and quicker. The controller has suggested that there may be a better approach.
Required:
1.	Using the high-low method, estimate a cost formula for utilities.