Let's go step by step to complete this calculation:

1. Filling in the missing balances and products

We need to fill in the missing balance entries first, and then the product/sum column based on the number of days.

For 9/7 - 9/18:

The balance remains the same as the previous day's balance, which is $337.52. The number of days is $18 - 7 + 1 = 12$.

So, for 9/7 - 9/18:

• Balance: $337.52
• Number of days: 12
• Product: $337.52 \times 12 = 4,050.24$

For 9/20 - 9/30:

The balance after the purchase of $62.26 on 9/19 is $399.78, and it remains the same until 9/30 (11 days).

So, for 9/20 - 9/30:

• Balance: $399.78
• Number of days: 11
• Product: $399.78 \times 11 = 4,397.58$

Total:

Now, let’s calculate the total of the products:

$1,937.60 \, (\text{for 9/1 - 9/5}) + 337.52 \, (\text{for 9/6}) + 4,050.24 \, (\text{for 9/7 - 9/18}) + 399.78 \, (\text{for 9/19}) + 4,397.58 \, (\text{for 9/20 - 9/30}) = 11,122.72$

2. Calculate the average daily balance:

The total of the product column is $11,122.72$, and the total number of days in the month is 30.

$\text{Average daily balance} = \frac{11,122.72}{30} = 370.76$

3. Finance charge:

The finance charge is calculated by multiplying the average daily balance by the monthly interest rate.

$\text{Finance charge} = 370.76 \times \frac{1.25}{100} = 4.63$

4. New balance:

The formula for the new balance is:

$\text{New balance} = \text{previous balance} - \text{payment/credits} + \text{finance charge} + \text{new purchases}$

From the given information:

• Previous balance = $387.52 (the initial balance on 9/1)
• Payments/Credits = $50.00 (on 9/6)
• New purchases = $62.26 (on 9/19)
• Finance charge = $4.63

So:

$\text{New balance} = 387.52 - 50 + 4.63 + 62.26 = 404.41$

Final Results:

1. Average daily balance: $370.76
2. Finance charge: $4.63
3. New balance: $404.41

Would you like more details or have any questions?

Here are 5 related questions for practice:

1. What would the finance charge be if the monthly interest rate was 1.5% instead of 1.25%?
2. How would the average daily balance change if an additional purchase was made on 9/15?
3. How does the average daily balance method differ from the adjusted balance method?
4. What would the new balance be if a second payment of $30 was made on 9/25?
5. How would a late payment fee affect the final balance calculation?

Tip: Always pay attention to the number of days in each period when calculating average daily balance, as it heavily impacts the final result!