Assume a bank offers an effective annual rate of 5.89%. If compounding is quarterly what is the APR?

1 answer

To calculate the Annual Percentage Rate (APR) given an effective annual rate (EAR) of 5.89% with quarterly compounding, we can use the relationship between the EAR, the APR, and the number of compounding periods per year.

The formula connecting these values is:

\[ EAR = \left(1 + \frac{APR}{n}\right)^n - 1 \]

Where:

  • \( EAR \) is the effective annual rate,
  • \( APR \) is the annual percentage rate,
  • \( n \) is the number of compounding periods per year.

In this case, the number of compounding periods \( n = 4 \) (quarterly compounding).

We rearrange the formula to solve for APR:

\[ 1 + EAR = \left(1 + \frac{APR}{n}\right)^n \]

Substituting the values:

\[ 1 + 0.0589 = \left(1 + \frac{APR}{4}\right)^4 \]

Calculating \(1 + EAR\):

\[ 1.0589 = \left(1 + \frac{APR}{4}\right)^4 \]

Next, we take the fourth root of both sides:

\[ 1 + \frac{APR}{4} = (1.0589)^{\frac{1}{4}} \]

Calculating \(1.0589^{\frac{1}{4}}\):

\[ 1 + \frac{APR}{4} \approx 1.01423 \]

Now, subtract 1 from both sides:

\[ \frac{APR}{4} \approx 0.01423 \]

Now, multiplying by 4 to find APR:

\[ APR \approx 0.01423 \times 4 \approx 0.05692 \]

Converting to percentage:

\[ APR \approx 5.692% \]

Thus, the APR is approximately 5.69%.