(CH9) Robby Co purchased a robot welder for $200,000 on July 1, 2020. It has an estimated salvage value of $20,000 and life of 500,000 units. The robot was used to produce the following units in its first four years. Compute the amount of depreciation expense for each year. 3 4 Units Produced 5 Depreciation 6 7 Year 12/31/20 12/31/21 12/31/22 12/31/23 8 9 10 12 Using the information above, what is the Net Book Value of the Robot Welder as of 12/31/23? 13 14 Net Book Value 12/31/23: is: $ 15 16 17 118