A depreciation schedule for heavy equipment of Beniluz Road Construction Company was requested by your auditor soon after December 31, 2015, showing the addi- tions, retirements, depreciation, and other data affecting the income of the company in the 4-year period 2012 to 2015, inclusive. The following data were ascertained.

Balance of Equipment account, Jan. 1, 2012

Equipment No. 1 purchased Jan. 1, 2009, cost: $ 50,000

Equipment No. 2 purchased July 1, 2009, cost: 60,000

Equipment No. 3 purchased Jan. 1, 2010, cost: 55,000

Equipment No. 4 purchased July 1, 2011, cost : 70,000

Balance, Jan. 1, 2012 $235,000

The Accumulated DepreciationEquipment account previously adjusted to January 1, 2012, and en- tered in the ledger, had a balance on that date of $89,000 (depreciation on the four pieces of equipment from the respective dates of purchase, based on a 5-year life, no salvage value). No charges had been made against the account before January 1, 2012.

Transactions between January 1, 2012, and December 31, 2015, which were recorded in the ledger, are as follows.

Jan 1. 2013 -- Equipment No. 1 was sold for $6,000 cash; entry debited Cash and credited Equipments, $6,000.

July 1 2013- Equipment No. 2 was traded for a larger one (No. 5), the agreed purchase price of which was $80,000. Beniluz Road Construction Co. paid the dealer $66,000 cash on the transaction. The entry was a debit to Equipment and a credit to Cash, $66,000. The transaction has commercial substance.

July 1 2014-- Equipment No. 3 was damaged in a wreck to such an extent that it was sold as junk for $500 cash. Beniluz Road Construction Co. received $12,000 from the insurance company. The entry made by the bookkeeper was a debit to Cash, $12,500, and credits to Miscellaneous Income, $500, and Equipment, $12,000.

July 1 2015-- A new Equipment (No. 6) was acquired for $92,000 cash and was charged at that amount to the Equipments account.

Entries for depreciation had been made at the close of each year as follows: 2012, $47,000; 2013, $42,600; 2014, $32,700; 2015, $35,400.

Instructions

(a) For each of the 4 years, compute separately the increase or decrease in net income arising from the companys errors in determining or entering depreciation or in recording transactions affecting equipment, ignoring income tax considerations.