It is April 30th and Greg, a small business owner, just had a busy month. He deposited multiple large checks throughout the month, including a $4,000 check on the final day of the month. He also wrote three checks of $100, $500, and $650 during the month. Greg noted that the bank balances were identical at the beginning of the month, but the bank balance is slightly higher than the book balance. Greg notes that there were no large bank collections or EFT receipts/payments during the month. What might be some items of concern for Greg as he completes the bank reconciliation (include possible journal entries)? What would the difference between the cash balances most likely be attributed to?