The Lone Star oil company located near Lubbock, TX wants to install a new pipeline to connect a storage tank with an existing pump that is at a distance of 1,000 feet. Three possible diameters are being considered to make the pipeline whose related costs are as follows:

Diameter	4 inches	6 inches	8 inches
Initial cost	$2,000	$3,000	$4,000
maintenance cost/year	600	500	400
Cost of pumping per year	2.70	1.30	1.00
Residual Value	100	150	300
Useful life (years)	10	10	10