Answer:
State Bank will suffer the loss on the check with the forged signature, while United will suffer it on the check with the forged endorsement.
Explanation:
When the signature of a drawer is forged, the drawer has not been negligent, and the drawee bank paid the check with the forged signature, it is the drawee bank who has to bear the loss, as it has to recredit the account of the affected drawer. On the other hand, when talking about a check with a forged endorsement, it is the bank that paid the check who suffer the loss. It must recredit the drawer's account, while the drawee bank can actually ask to recover the amount from the bank that paid the check.
In this case, State Bank was the drawee bank for both checks, but it only has to recredit Pauline for the check with the forged signature. United is responsible for recrediting Pauline for the check with the forged endorsement, however, while State Bank can recover the amount from them. State Bank and United can try to recover their losses from Nick, but this can prove very difficult.