Davis Stores sells clothing in 15 stores located around the southwestern United States. The managers at Davis are considering expanding by opening new stores and are interested in estimating costs in potential new locations. They believe that costs are driven in large part by store volume measured by revenue. The following data were collected from last years operations (revenues and costs in thousands of dollars).

Store	Revenues	Costs
101	$4,150	$4,289
102	2,277	2,994
103	5,813	5,256
104	4,082	4,123
105	2,989	3,826
106	4,123	3,494
107	6,944	5,104
108	1,854	2,624
109	5,666	4,888
110	3,378	3,109
111	3,986	4,304
112	4,815	3,300
113	3,602	2,706
114	5,017	4,755
115	2,374	3,061

Required

a. Use the high-low method to estimate the fixed and variable portions of store costs based on revenues.

b. Managers estimate that one of the proposed stores will have revenues of $3.0 million. What are the estimated monthly overhead costs, assuming no inflation?

c. Managers are also considering a mega-store with revenues of $15 million. What are the estimated monthly overhead costs, assuming no inflation?