Zeigler Manufacturing Company purchased a robot for $720,000 at the beginning of year 1. The robot has an estimated useful life of four years and an estimated residual value of $60,000. The robot, which should last 20,000 hours, was operated 6,000 hours in year 1; 8,000 hours in year 2; 4,000 hours in year 3; and 2,000 hours in year 4.

1. Compute the annual depreciation and carrying value for the robot for each year assuming the following depreciation methods:

a. Straight-line

b. Production

c. Double-declining-balance

2. If the robot is sold for $750,000 after year 2, what would be the amount of gain or loss under each method?

a.	Straight-line:
b.	Production:
c.	Double-declining-balance: