Hamid is a 9-1-1 operator. when the blizzard began, he was told he would have to stay and work three extra shifts to cover for coworkers who were not able to drive to work through the storm. after 32 hours of exhausting work, he makes it home and discovers he is able to fall asleep faster and gets into rem sleep quicker. hamid may be experiencing .

You are considering the purchase of one of two machines used in your manufacturing plant. machine 1 has a life of two years, costs $20,000 initially, and then $4,000 per year in maintenance costs. machine 2 costs $25,000 initially, has a life of three years, and requires $3,500 in annual maintenance costs. either machine must be replaced at the end of its life with an equivalent machine. using eac which is the better machine for the firm