Answer:
The old machine should be retained.
Explanation:
[tex]\left[\begin{array}{cccc}&continue&replace&Differential\\Proceeds \: from \: sale&0&27,200&27,200&Cost:&&&&purchase&0&-407,400&-407,400&manufacturing\:cost&-4,480,700&-4,422,600&58,100&Total \:cost&-4,480,700&-4,830,000&-349,300&Net&-4,480,700&-4,802,800&-322,100&\end{array}\right][/tex]
The old machine should be retained.
The differential analisys shows cost will increase 322,100 if replaced.
The sale from the old machine is an income for the relacement alternative.
the cost of the new machine is an expense
the value of the 7 years of manufacturing cost show a cost saving for 58,100
this savings, along with the proceeds from the old machine, doesn't cover the acquisition of the new machine. It is a bad investment.