To determine the final balance in Bill's account, we start with his initial balance of $270.61. We then process each transaction step by step: First, we add the paycheck of $535.67 to the initial balance, resulting in $806.28. Next, we subtract the electric bill of $112.53, bringing the balance down to $693.75. We then subtract the groceries expense of $90.79, which reduces the balance to $602.96. After that, we add the savings bond deposit of $50.00, increasing the balance to $652.96. Finally, we subtract the car payment of $225.65, resulting in a final balance of $427.31. Thus, the correct answer is $427.31.