On May 5, 2017, Lloyd purchased a machine for $84,000. The estimated life of the machine was 10 years, with an estimated residual value of $10,000. The service life in terms of output is estimated at 8,000 hours of operation. Assume Lloyd uses the units-of-output method and that the machine was in operation for 1,000 hours in 2017 and 1,800 hours in 2018. The book value of the machine at December 31, 2017 is:

$66,700

$74,750

$75,900

$78,100