Sales, which is the amount of credit sales, less cash sales, made during the accounting period. Question 15 3.7 pts Hoosier Hospital bought an X-Ray machine for $88,000 cash. Set up and testing costs necessary before the equipment could be used totaled $4,500. The machine has a 10 -year estimated life and $1,000 residual value. What is the net book value of the machine at the end of year 4 ? None of the answers are correct $50,500 $55,900 $55,100 $53,200