Answer:
<u>Straight line:</u>
2014 $ 65,250  
2015 $  87,000  
2016 $  87,000  
2017 $   21,750
<u>units-of-output method:</u>
2014 $ 108,750
2015 $   79,750
2016 $  58,000
2017  $   14,500
<u>dobule declining method</u>
2014  135,000   
2015  45,000   
2016  15,000   
2017  9,000   
Explanation:
<u>Straight line:</u>
(cost - salvage value) / useful life
(270,000 - 9,000)/3 = 87,000 per complete year
First year: from April 1st to December 31th
87,000 x 9/12 = 65,250
Second and third year are complete year thus, 87,000
fourth year: from Jan 1st to March 31th:
87,000 x 3/12 = 21,750
<u>units-of-output method:</u>
(cost - salvage value) / unit of output
261,000 / 18,000 = 14.5 per hour
We multiply each year hours by this rate
7,500 x 14.5 = 108,750
5,500x 14.5 =   79,750
4,000x 14.5 =   58,000
1,000 x 14.5 =   14,500
<em><u>double declining </u></em>
we multiply by twice the rate of of straight line:
1/3 x 2 = 2/3 we depreciate this amount of the carrying vbalue per year
Last year we adjust to obtain the residual value
 Year   Beginning   Rate   Dep expense   Carrying value 
 2014     270,000     0.50     135,000     135,000   
 2015     135,000     0.67     90,000     45,000   
 2016     45,000     0.67     30,000     15,000   
 2017     15,000                6,000      9,000