$12\mathrm{.}10$ A local U$.$S$.$ Postal Service office is consider$-$

ing purchasing a $4,000-$pound forklift truck, which

will be used primarily for processing incoming as

well as outgoing postal packages. Forklift trucks tra$-$

ditionally have been fueled by either gasoline, liquid

propane gas $($LPG$),$ or diesel fuel. Battery$-$powered

electric forklifts, however, are increasingly popular

in many industrial sectors due to the economic and

environmental benefits that accrue from their use.

Therefore, the postal service is interested in compar$-$

ing forklifts that use the four different types of fuel

$($Table P$12\mathrm{.}10).$ The purchase costs as well as annual

operating and maintenance costs are provided by a

local utility company and the Lead Industries Asso$-$

ciation. Annual fuel and maintenance costs are meas$-$

ured in terms of number of shifts per year, where one

shift is equivalent to eight hours of operation.

The postal service is unsure of the number of shifts

per year, but it expects it should be somewhere

between $200$ and $260$ shifts. Since the U$.$S$.$ Postal

Service does not pay income taxes, no depreciation

or tax information is required. The U$.$S$.$ government

uses $10\%$ as an interest rate for any project evalua$-$

tion of this nature. Develop a sensitivity graph that

shows how the choice of alternatives changes as a

function of number of shifts per year.

$($Please use Excel and show the equations used and plot present values vs the number of shifts$)$