Answer:
CRUZ COMPANY
1. Closing Entries:
No. Account Title             Debit      Credit
901 Income Summary  $33,100
612 Depreciation expense
—Equipment                                  $3,000
622 Salaries expense                  22,000
637 Insurance expense                 2,500
640 Rent expense                         3,400
652 Supplies expense                  2,200
To close expenses to the Income Summary.
404 Services revenue $44,000
901 Income Summary                    $44,000
To close Service Revenue to the Income Summary.
318 Retained earnings $37,600
901 Income Summary (Retained Earnings) $37,600
To close the Retained Earnings of prior year to Retained Earnings section of the Income Summary.
901 Income Summary 
     (Retained Earnings) $7,000
319 Dividends                                    $7,000
To close the Dividends to the Retained Earnings section of the Income Summary.
2. CRUZ COMPANY
Post-Closing Trial Balance
As of December 31
No. Account Title             Debit      Credit
101 Cash                        $ 19,000
126 Supplies                    13,000
128 Prepaid insurance     3,000
167 Equipment               24,000
168 Accumulated depreciation
—Equipment                                  $ 7,500
307 Common stock                        10,000
318 Retained earnings                    41,500
Totals                        $ 59,000   $ 59,000
Explanation:
a) Data and Calculations:
CRUZ COMPANY
Trial Balance 
As of December 31
No. Account Title             Debit      Credit
101 Cash                        $ 19,000
126 Supplies                    13,000
128 Prepaid insurance     3,000
167 Equipment               24,000
168 Accumulated depreciation
—Equipment                                  $ 7,500
307 Common stock                        10,000
318 Retained earnings                   37,600
319 Dividends                  7,000
404 Services revenue                   44,000
612 Depreciation expense
—Equipment                    3,000
622 Salaries expense  22,000
637 Insurance expense 2,500
640 Rent expense         3,400
652 Supplies expense 2,200
Totals                        $ 99,100    $ 99,100
b) Income Summary for the year ended December 31:
Revenue                   $44,000
Expenses                   (33,100)
Net Income              $10,900
Retained Earnings    37,600
Dividends                  (7,000)
Retained Earnings $41,500