how is this not complete

Posting errors are identified in the following table. In column (1), enter the amount of the difference between the two trial balance columns (debit and credit) due to the error. In column (2), identify the trial balance column (debit or credit) with the larger amount if they are not equal. In column (3), identify the account(s) affected by the error. In column (4), indicate the amount by which the account(s) in column (3) is under- or overstated. Item (a) is completed as an example, (Select "None" if there is no effect.) Answer is not complete. Description of Posting Error (1) Difference between Debit and Credit Columns (2) Column with the Larger Total Identify Account(s) Incorrectly stated Amount That Account(s) Over or Understated a. $ 270 Credit Rent Expense Rent Expense is understated by $270 $1,960 debit to Rent Expense is posted as a $1,690 debit $3,920 credit to Cash is posted twice as two credits to Cash b. $ 3.920 Credit Cash Cash is understated by $3,920 C. $7,840 debit to the Dividends account is debited to Common Stock $ 0 None > Common stock Common stock is understated by $7,840 d. $1,810 debit to Prepaid Insurance is posted as a debit to Insurance Expense. None Prepaid insurance Insurance expense is overstated by $1,810 e. $34,300 debit to Machinery is posted as a debit to Accounts Payable. $ 0 None Machinery Machinery is understated by $34,300 1 $4,820 credit to Services Revenue is posted as a $482 credit. $ 4,338 Debit Services revenue Services revenue is understated by $4,338 9 $1,000 debit to Store Supplies is not posted. $ 1,000 Credit Store supplies Store supplies is understated by $1,000 Prey A of 7 Next >