Questions: On September 7, the billing date, Verna had a balance due of 566.35 on her credit card. Assume that the interest rate is 1.1% per month. Suppose that Verna's bank uses the average daily balance method. Answer parts (a) through (d).
Sept. 10 Payment 260.00
Sept. 23 Charge: Airline ticket 332.00
Sept. 24 Charge: Hotel bill 192.02
Oct. 1 Charge: Clothing 84.76
a) Determine Verna's average daily balance for the billing period from September 7 to October 7.
The average daily balance for the billing period was . (Round to the nearest cent as needed.)
Transcript text: On September 7 , the billing date, Verna had a balance due of $\$ 566.35$ on her credit card. Assume that the interest rate is $1.1 \%$ per month. Suppose that Verna's bank uses the average daily balance method. Answer parts (a) through (d).
\begin{tabular}{|l|l|r|}
\hline Sept. 10 & Payment & $\$ 260.00$ \\
\hline Sept. 23 & Charge: Airline ticket & $\$ 332.00$ \\
\hline Sept. 24 & Charge: Hotel bill & $\$ 192.02$ \\
\hline Oct. 1 & Charge: Clothing & $\$ 84.76$ \\
\hline
\end{tabular}
a) Determine Verna's average daily balance for the billing period from September 7 to October 7.
The average daily balance for the billing period was $\$$ $\square$ .
(Round to the nearest cent as needed.)
Solution
Solution Steps
Step 1: Initial Setup
We start with Verna's initial balance on September 7, which is given as \( B_0 = 566.35 \).
Step 2: Transactions and Balance Changes
We will track the balance changes due to the transactions that occur during the billing period:
September 10: Payment of \( 260.00 \)
\[
B_1 = B_0 - 260.00 = 566.35 - 260.00 = 306.35
\]
September 23: Charge for an airline ticket of \( 332.00 \)
\[
B_2 = B_1 + 332.00 = 306.35 + 332.00 = 638.35
\]
September 24: Charge for a hotel bill of \( 192.02 \)
\[
B_3 = B_2 + 192.02 = 638.35 + 192.02 = 830.37
\]
October 1: Charge for clothing of \( 84.76 \)
\[
B_4 = B_3 + 84.76 = 830.37 + 84.76 = 915.13
\]
Step 3: Calculate Days for Each Balance
Next, we calculate the number of days each balance was in effect:
From September 7 to September 10: \( 3 \) days at \( 566.35 \)
From September 10 to September 23: \( 13 \) days at \( 306.35 \)
From September 23 to September 24: \( 1 \) day at \( 638.35 \)
From September 24 to October 1: \( 7 \) days at \( 830.37 \)
From October 1 to October 7: \( 6 \) days at \( 915.13 \)
Step 4: Calculate Total Balance Days
Now we calculate the total balance days:
\[
\text{Total Balance Days} = (3 \times 566.35) + (13 \times 306.35) + (1 \times 638.35) + (7 \times 830.37) + (6 \times 915.13)
\]
Calculating each term:
The total number of days in the billing period is \( 30 \) days (from September 7 to October 7). Thus, the average daily balance is calculated as:
\[
\text{Average Daily Balance} = \frac{\text{Total Balance Days}}{\text{Total Days}} = \frac{17623.32}{30} = 587.44
\]
Final Answer
The average daily balance for the billing period was \( \boxed{587.44} \).