In two to four sentences, explain economies of scale.

Amachine purchased three years ago for $720,000 has a current book value using straight-line depreciation of $400,000: its operating expenses are $60,000 per year. a replacement machine would cost $480,000, have a useful life of nine years, and would require $26,000 per year in operating expenses. it has an expected salvage value of $130,000 after nine years. the current disposal value of the old machine is $170,000: if it is kept 9 more years, its residual value would be $20,000. calculate the total costs in keeping the old machine and purchase a new machine. should the old machine be replaced?

"in my opinion, we ought to stop making our own drums and accept that outside supplier's offer," said wim niewindt, managing director of antilles refining, n.v., of aruba. "at a price of $21 per drum, we would be paying $4.70 less than it costs us to manufacture the drums in our own plant. since we use 70,000 drums a year, that would be an annual cost savings of $329,000." antilles refining's current cost to manufacture one drum is given below (based on 70,000 drums per year):

Imagine you own an established startup with growing profits. you are looking for funding to greatly expand company operations. what method of financing would be best for you?