Sweeney \& Allen, a large marketing firm, adjusts its accounts at the end of each month. The following information is available for the year ending December 31. 1. A bank loan had been obtained on December 1. Accrued interset on the loan at December 31 amounts to $1,500. No interest expense has yet been recorded. 2. Depreciation of the firm's office building is based on an estimated life of 30 years. The building was purchased four years ago for $450,000. 3. Accrued, but unbilled, revenue during December amounts to $75,000. 4. On March 1, the firm paid $2,400 to renew a 12 -month insurance policy. The entire amount was recorded as Prepaid Insurance. 5. The firm received $15,000 from King Biscuit Company in advance of developing a six-month marketing campaign. The entire amount was initially recorded as Inearned REvenue. 6. The company's policy is to pay its employees every Friday. Because December 31 fell on a Wednesday, there was an accrued liability for salaries amounting to $1,900. a. Record the necessary adjusting journal entries on December 31. b. By how much did Sweeney \% Allen's net income increase or decrease as a result of the adjusting entries performed in part a? (Ignore income taxes.)