The following data relate to the Machinery account of Rose Enterprises on 12/31/17:

			Mach A	Mach B	Mach C	Mach D
Original cost			46,000	51,000	80,000	80,000
Year purchased			2012	2013	2014	2016
Useful life			10 years	15,000 hrs	15 years	10 years
Salvage value			3,100	3,000	5,000	5,000
Depreciation method			SYD	Activity	S/L	DDB
Accum deprec thru 2017			31,200	35,200	15,000	16,000

It is company policy to not record depreciation expense in the year purchased. A full years depreciation is taken in the year an asset is retired or traded in.

During 2018, the following transactions occurred:

1. On May 5, Machine A was sold for $ 13,000 cash. The firms bookkeeper recorded the retirement with a debit to Cash and a credit to Machinery for $13,000;

2. On December 31, it was determined that Machine B had been used 2,100 hours during 2018;

3. On December 31, before calculating depreciation expense on Machine C, management decided the useful life remaining from January 1, 2018, was 10 years;

4. On December 31, it was discovered that a machine purchased in 2017 had been expensed completely in that year. This machine cost $ 28,000 and has a useful life of 10 years with no salvage value. Management has decided to use the double-declining-balance method for this machine, which was referred to as Machine E.

a. Prepare any necessary correcting entries for 2018.

b. Record the appropriate depreciation expense for each of the above-mentioned machines.

c. What account(s) and amount(s) would appear on a 2018 income statement?

d. For each machine, what is the net book value as of 12/31/18?