$11-22$ Relevant and irrelevant costs. Answer the following questions.

Robinson Computers makes $5,700$ units of a circuit board, CB$76,$ at a cost of $$230$ each. Variable cost per

unit is $$180$ and fixed cost per unit is $$50.$ Peach Electronics offers to supply $5,700$ units of CB$76$ for $$210.$

If Robinson buys from Peach, it will be able to save $$20$ per unit in fixed costs but continue to incur the

remaining $$30$ per unit. Should Robinson accept Peach's offer? Explain.

RT Manufacturing is deciding whether to keep or replace an old machine. It obtains the following

information:

RT Manufacturing uses straight$-$line depreciation. Ignore the time value of money and income taxes. Should RT

Manufacturing replace the old machine? Explain.