N his book Naked Economics, Charles Wheelan discusses the falling birth rate in industrialized countries like Japan and the United States. He writes that the main cost of child rearing today is the cost of forgone earnings when a parent stops or cuts back working in order to raise a child. The earnings that parents forgo to raise children are an example of cost.

Xinhong company is considering replacing one of its manufacturing machines. the machine has a book value of $39,000 and a remaining useful life of 5 years, at which time its salvage value will be zero. it has a current market value of $49,000. variable manufacturing costs are $33,300 per year for this machine. information on two alternative replacement machines follows. alternative a alternative b cost $ 115,000 $ 117,000 variable manufacturing costs per year 22,900 10,100 1. calculate the total change in net income if alternative a and b is adopted. 2. should xinhong keep or replace its manufacturing machine