Question

what was the balance immediately before the deposit on september 20?
d = deposit ap = automatic payment atm = cash withdrawal dc = debit card sc = service charge
date\tcode or check #\ttransaction description\tpayment, fee, withdrawal (—)\t√\tdeposit, credit (+)\tbalance
9/04\t412\tpiano lessons\t64\t00\t\t\t564\t24
9/07\t413\telectrician\t245\t15\t\t\t319\t09
9/13\tdc\tgroceries\t120\t62\t\t\t198\t47
9/20\td\tpaycheck\t\t\t724\t50\t922\t97
9/28\tap\tcar payment\t204\t46\t\t\t718\t51
10/03\t414\tpiano lessons\t64\t00\t\t\t654\t51
10/06\t415\tphone bill\t145\t34\t\t\t509\t17

Explanation:

Step1: Identify the deposit date

We need to find the balance before the deposit on September 20 (9/20). First, look at the transactions before 9/20. The last transaction before 9/20 is on 9/13 (or check the balance column progression). Wait, actually, let's track the balance column. Wait, the balance before the deposit on 9/20: let's see the transactions. Wait, the deposit on 9/20: the balance before that would be the balance from the previous transaction (before 9/20) and then any withdrawals/deposits before. Wait, looking at the balance column: let's list the dates and balances:

- 9/04: Balance 628.24 (wait, the balance column has numbers like 628, 564, 319, 198, 922, 718, 654, 509... Wait, maybe the balance is cumulative. Wait, the deposit on 9/20: the balance before the deposit would be the balance from the transaction before 9/20. Let's check the transactions:

Looking at the date 9/20, code D (deposit). The previous transaction is on 9/13 (DC, Groceries, payment 120.62, balance 198.47? Wait, no, maybe I misread. Wait, let's look at the balance column. Wait, the balance after each transaction:

Wait, the first balance is 628.24 (9/04), then 564.24 (9/07: payment 64.00? Wait, 628 - 64 = 564? Then 564 - 245 -15 = 564 - 260 = 304? But the balance is 319.09? Maybe there's a deposit or I misread. Wait, maybe the balance is calculated as previous balance + deposit - payment/withdrawal.

Wait, the deposit on 9/20: we need the balance before that deposit. Let's track the balance from the last transaction before 9/20. Let's see the transaction on 9/13: DC (debit card), Groceries, payment 120.62, balance 198.47. Then on 9/20, code D (deposit). Wait, no, the balance before the deposit on 9/20 would be the balance from the transaction before 9/20, which is 9/13's balance? Wait, no, maybe the balance before 9/20 is the balance from 9/13, then any transactions between 9/13 and 9/20? Wait, the dates are 9/04, 9/07, 9/13, 9/20, 9/28, etc.

Wait, looking at the balance column:

- 9/04: 628.24

- 9/07: 564.24 (628 - 64 = 564? 64 is the payment on 9/07)

- 9/13: 319.09 (564 - 245 -15 = 564 - 260 = 304, but it's 319.09, maybe a deposit? Wait, no, 9/13 is DC (debit card), Groceries, payment 120.62. Wait, 564 - 245 (electrician) -15 (fee) = 564 - 260 = 304, then 304 - 120.62 = 183.38? But the balance is 198.47. Maybe I'm misreading the columns. Wait, the "Payment, Fee, Withdrawal (-)" column: for 9/07, it's 245.15 (payment), so 628.24 - 245.15 = 383.09? No, the balance is 319.09. Wait, maybe the balance is previous balance - payment + deposit? Wait, 9/04: balance 628.24

9/07: payment 245.15, so 628.24 - 245.15 = 383.09? But the balance is 319.09. Then 9/13: payment 120.62, 383.09 - 120.62 = 262.47? No, balance is 198.47. Wait, maybe the "Deposit, Credit (+)" column: for 9/07, is there a deposit? No, 9/07 is payment. Wait, maybe the balance is cumulative with deposits and withdrawals. Wait, the deposit on 9/20: the balance before that deposit would be the balance from the transaction before 9/20, which is 9/13's balance. Wait, looking at the balance column, the balance before 9/20 (date 9/20) is the balance from the previous transaction, which is 9/13's balance: 198.47? Wait, no, the balance on 9/13 is 198.47, then on 9/20, it's a deposit. Wait, but the balance after 9/20 is 922.50 (since 198.47 + 724.50 = 922.97? Wait, the deposit on 9/20 is 724.50 (credit column: 724.50). So balance before deposit = balance after previous transaction (before 9/20) = 198.47? Wait, no, let's check the balance column. The balance before 9/20: looking at the balance column, the row before 9/20 (date 9/20) is 9/13, balance 198.47. Then on 9/20, deposit (D) with credit 724.50, so balance becomes 198.47 + 724.50 = 922.97 (which matches the balance column: 922.50? Wait, maybe a typo, but the key is that the balance before the deposit on 9/20 is the balance from the previous transaction, which is 198.47? Wait, no, wait the balance column for 9/20 is 922.50, and the credit is 724.50, so previous balance = 922.50 - 724.50 = 198.00? Wait, 922.50 - 724.50 = 198. So the balance before the deposit on 9/20 is 198.47? Wait, looking at the balance column, the row before 9/20 (date 9/13) has balance 198.47. So that's the balance before the deposit on 9/20.

Wait, maybe I made a mistake, but let's check the balance column:

- 9/04: 628.24

- 9/07: 564.24 (628.24 - 64.00 = 564.24? 64 is the payment on 9/07)

- 9/13: 564.24 - 245.15 -15.00 = 564.24 - 260.15 = 304.09? But balance is 319.09. Wait, maybe there's a deposit on 9/13? No, 9/13 is DC (debit card), payment 120.62. Wait, 564.24 - 245.15 -15.00 -120.62 = 564.24 - 380.77 = 183.47? No, balance is 319.09. I think I'm misreading the columns. Wait, maybe the "Payment, Fee, Withdrawal (-)" column is the amount subtracted, and "Deposit, Credit (+)" is added. Let's re-express:

For each transaction:

- Date 9/04: Check #412, Piano lessons, payment 64.00, balance 628.24 (maybe initial balance)

- Date 9/07: Check #413, Electrician, payment 245.15, fee 15.00? Wait, no, the columns: "Payment, Fee, Withdrawal (-)" has two numbers? Wait, maybe the first number is dollars, second is cents. So 64.00, 245.15, 120.62, 204.46, 64.00, 145.34.

So balance calculation:

Start with 628.24 (9/04)

9/07: subtract 245.15 (payment) and 15.00 (fee? Wait, no, maybe the "Payment, Fee, Withdrawal (-)" is total amount: 245 +15 = 260? 628 - 260 = 368? No, balance is 319.09. Wait, maybe the "Deposit, Credit (+)" column is added. Wait, 9/07: no deposit. 9/13: DC (debit card), payment 120.62, balance 319.09 - 120.62 = 198.47 (which matches the next balance). Ah! So:

9/04: 628.24

9/07: 628.24 - 245.15 -15.00? No, 628.24 - 245.15 = 383.09, then -15.00 = 368.09? No, balance is 319.09. Wait, maybe the "Payment, Fee, Withdrawal (-)" is 245.15 (payment) and 15.00 (fee), total 260.15. 628.24 - 260.15 = 368.09. Then 9/13: payment 120.62, 368 - 120.62 = 247.38? No, balance is 198.47. I'm confused. Wait, the balance column after 9/13 is 198.47, then 9/20: deposit (D) with credit 724.50, so balance becomes 198.47 + 724.50 = 922.97, which is the balance on 9/20 (922.50? Maybe rounding). So the balance before the deposit on 9/20 is 198.47. Wait, but looking at the balance column, the row before 9/20 (date 9/20) is 9/13, balance 198.47. So that's the balance before the deposit.

Step2: Confirm the balance

So the balance immediately before the deposit on September 20 is the balance from the transaction before 9/20, which is 198.47 (or looking at the balance column, the balance before 9/20 is 198.47). Wait, but the balance column for 9/13 is 198.47, then 9/20 is 922.50 (198.47 + 724.03? No, 724.50). So the balance before the deposit is 198.47. Wait, maybe the answer is 922.50 - 724.50 = 198.00 (rounding). So the balance before the deposit on September 20 is 198.47 (or 198.00, depending on rounding). But looking at the balance column, the balance before 9/20 is 198.47.

Answer:

198.47 (or 198.00, but based on the balance column, 198.47)