straight line depreciation
	
	
		I am really confused to calculate the Depriciation expense for Dec, 2008. The question is like this. 
In 2007, Cost of truck is $22,000, estimated life year is 5 years, and salvage value is $2000. The recorded annual straight line depreciation for December 2007 is $4000 as I recorded. 
1n 2008, the truck's estimated useful life was changed from five to four years and salvage value is $2400.I need to record the annual Straight line  depreciation on the truck. According to my calculations, it is $4900, but when I match the answer, it should be equal to $5,200. Can anybody help me please. I AM VERY VERY CONFUSED