Starling Co. is considering disposing of a machine with a book value of $21,100 and estimated remaining life of five years. The old machine can be sold for $5,300. A new high-speed machine can be purchased at a cost of 68,000. It will have a useful life of five years and no residual value. It is estimated that the annual variable manufacturing costs will be reduced from $22,500 to $20,100 the new machine is purchased. The differential effect on income for the new machine for the entire five years is decrease of 50,700 decrease of $65,910 increase of $65,910 increase of $50,700