1. **State the problem:**
Alana made a purchase of 1850 on May 01. On June 01, after making a minimum payment of 35, her new balance was 1845.77. We need to find the nominal interest rate compounded daily.
2. **Understand the situation:**
The interest is charged daily on the remaining balance from the date of purchase if the full balance is not paid.
3. **Set up the formula:**
The balance after interest is calculated by compound interest formula:
$$A = P \left(1 + \frac{r}{n}\right)^{nt}$$
where:
- $A$ is the amount after interest,
- $P$ is the principal (initial balance after payment),
- $r$ is the nominal annual interest rate (to find),
- $n$ is the number of compounding periods per year (daily compounding means $n=365$),
- $t$ is the time in years.
4. **Calculate the principal after payment:**
Initial balance: 1850
Payment: 35
Remaining principal after payment:
$$P = 1850 - 35 = 1815$$
5. **Calculate time $t$:**
From May 01 to June 01 is 31 days.
Convert to years:
$$t = \frac{31}{365}$$
6. **Plug values into the formula and solve for $r$:**
$$1845.77 = 1815 \left(1 + \frac{r}{365}\right)^{31}$$
Divide both sides by 1815:
$$\frac{1845.77}{1815} = \left(1 + \frac{r}{365}\right)^{31}$$
$$1.0169 = \left(1 + \frac{r}{365}\right)^{31}$$
7. **Take the 31st root:**
$$\left(1.0169\right)^{\frac{1}{31}} = 1 + \frac{r}{365}$$
Calculate left side:
$$1.00054 = 1 + \frac{r}{365}$$
8. **Solve for $r$:**
$$\frac{r}{365} = 1.00054 - 1 = 0.00054$$
Multiply both sides by 365:
$$r = 0.00054 \times 365 = 0.1971$$
9. **Convert to percentage and round:**
$$r = 19.71\%$$
**Final answer:** The nominal interest rate compounded daily is **19.71\%**.
Credit Card Interest 6E66F0
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