Five years ago. Miller Manufacturing spent exist150,000 on a new piece of industrial machinery. Six months ago, the firm spent exist32,000 on upgrades to the machinery. Currently, Miller is considering whether to replace the existing machine with newer machinery with a purchase price of exist180,000. When conducting the incremental analysis related to this decision, Miller should consider all of the following factors except any salvage value associated with the new machinery. the cost of the upgrades to the old machinery. any salvage value associated with the old machinery. any differences in the variable costs associated with each piece of machinery