Roanoke Manufacturing placed a robotic arm on a large assembly machine on January 1. At that time, the assembly machine was expected to last another 3 years. The following information is available concerning the assembly machine. The robotic arm cost $210,000 and was expected to extend the useful life of the machine by 3 years. Therefore, the useful life of the assembly machine, ofter the arm replacement, is 6 years. The assembly machine is expected to have a residual value of $123,000 at the end af its useful life. Required: 1. Prepore the fournal entry necessary to record the addition of the robotic arm, If an amaunt box does not require an entry, leave it blank. 2. Compute the revised amount of depreciation expense for the machine using the straight-line method. Prepare the necessary joumal entry to record depreciation expense, If an amount box does not require an entry, leave it blank. Dec. 31 3. What is the book value of the machine at December 31