Answer and Explanation:
The computation of the depreciation expense for the first year is shown below: 
1) Straight-line method: 
= (Original cost - residual value) ÷ (useful life) 
= ($16,000 - $1,600) ÷ (4 years) 
= ($14,400) ÷ (4 years) 
= $3,600
In this method, the depreciation is same for all the remaining useful life 
(2) Double-declining balance method: 
First we have to calculate the depreciation rate which is given below: 
= One ÷ useful life 
= 1 ÷ 4 
= 25% 
Now the rate is double So, 50% 
In year 1, the original cost is $16,000, so the depreciation is $8,000 after applying the 50% depreciation rate 
(c) Activity based method: 
= (Original cost - residual value) ÷ (estimated production) 
= ($16,000 - $1,600) ÷ (15,000 hours) 
= ($14,400) ÷ (15,000 hours) 
= $0.96 per hour
Now for the first year, it would be 
= Production hours in first year × depreciation per hour
= 2,100 hours × $0.96
= $2,016