Answer:
Book value at the end of year 3 of the machine: $130,000
Step-by-step explanation:
The company uses straight-line depreciation method, Depreciation Expense each year is calculated by following formula:
Depreciation Expense = (Cost of machine − Residual Value )/Useful Life = ($400,000-$40,000)/4 = $90,000
At the end of year 3, Accumulated depreciation = $90,000 x 3 = $270,000
Book value of the machine is: the machine's cost minus the machine's accumulated depreciation.
At the end of year 3, Book value of the machine = $400,000 - $270,000 = $130,000