The Lakeshore Hotels guest-days of occupancy and custodial supplies expense over the last seven months were:

Month	Guest-Days of Occupancy		Custodial Supplies Expense
March	8,000		$	11,200
April	7,500		$	11,000
May	10,000		$	12,000
June	11,500		$	12,600
July	13,500		$	13,400
August	12,500		$	13,000
September	10,000		$	12,000

Guest-days is a measure of the overall activity at the hotel. For example, a guest who stays at the hotel for three days is counted as three guest-days.

I need the high-low method, estimate a cost formula for custodial supplies expense, used the cost formula you derived above (what amount of custodial supplies expense would you expect to be incurred at an occupancy level of 12,300 guest-days?) and a scattergraph.