Engineering Economy 16th Edition by William Sullivan ,Elin Wicks, Koelling,

Exercise 6

Unless stated otherwise, discrete compounding of interest and end-of-period cash flows should be assumed in all problem exercises for the remainder of the book. All MARRs are "per year." The number in parentheses that follows each problem refers to the section from which the problem is taken.
A large induced-draft fan is needed for an upgraded industrial process. The motor to drive this fan is rated at 100 horsepower, and the motor will operate at full load for 8,760 hours per year. The motor's efficiency is 92%. Because the motor is fairly large, a demand charge of $92 per kilowatt per year will be incurred in addition to an energy charge of $0.08 per kilowatt-hour. If the installed cost of the motor is $4,000, what is the present worth of the motor over a 10-year period when the MARR is 15% per year