Roanoke Manufacturing ploced 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 avallable 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, after the arm replacement, is 6 years. The assembly machine is expected to have a residual value of $123,000 at the end of its useful life. Required: 1. Prepare the foumal entry necessary to record the addition of the robotic arm. If an amount box does not require an entry, leave it blanik, 3an. 1 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. bec. 31 3. What is the book value of the machine at December 31