Answer:
The correct answer is add $72 to the book's balance.
Step-by-step explanation:
Bank reconciliation is a way of identifying discrepancies between the cash book balance (company's books) and the bank balance (balance per bank statement). The discrepancies can be as a result of erroneous posting, deposit in transit, outstanding checks, etc.
In the instance of the question, there was an erroneous posting in the cash book of $72 ($480 - $408). Instead of crediting cash book by $408, it was rather credited by $480 - meaning that the credit was overstated by $72. To correct this erroneous posting, we have to add back $72 to the cash book balance.