Answer:
Erin must first reconcile her bank account:
She must add to her bank balance all the deposits in transit = $125.56 + $50 + $212.34 = $387.90
then she should subtract all outstanding checks = $15 + $78.25 = $93.25
reconciled bank statement = $844.93 + $387.90 - $93.25 = $1,039.58
if her check register shows a $1,150.34 balance and her reconciled bank statement is $1,039.58, then there is a $10.76 difference that must be accounted for.
The $10.76 are probably bank fees and charges that Erin has not recorded yet. Therefore, she should check her bank statement and look for any charged fees (ATM withdrawal charges + account fees) and then record them properly.
*ATM withdrawals are automatically recorded by the bank, so they do not have to be considered in the reconciliation, there is no such thing as outstanding ATM withdrawal.