Darnell Company paid \(\$ 67,500\) for a machine that was expected to last six years and have a salvage value of \(\$ 9,000\). Present general journal entries dated December 31 to record the following costs related to the machine.

a. During the second year of the machine's life, \(\$ 1,350\) was paid for repairs necessary to keep the machine in good working order.

b. During the third year of the machine's life, \(\$ 6,900\) was paid for replacement parts that were expected to increase the machine's productivity by \(15 \%\) each year.

c. During the fourth year of the machine's life, \(\$ 9,300\) was paid for repairs that were expected to increase the service life of the machine from six to eight years.