A bank offers 6.00% on savings accounts. What is the effective annual rate if interest is compounded quarterly?

1 answer

To calculate the effective annual rate (EAR) when the interest is compounded quarterly, you can use the formula:

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

where:

  • \( r \) is the nominal interest rate (as a decimal),
  • \( n \) is the number of compounding periods per year.

In this case:

  • \( r = 6.00% = 0.06 \)
  • \( n = 4 \) (since the interest is compounded quarterly)

Now, plug the values into the formula:

\[ \text{EAR} = \left(1 + \frac{0.06}{4}\right)^4 - 1 \]

Calculating \( \frac{0.06}{4} \):

\[ \frac{0.06}{4} = 0.015 \]

Now substitute back into the formula:

\[ \text{EAR} = \left(1 + 0.015\right)^4 - 1 \]

\[ = (1.015)^4 - 1 \]

Now calculate \( (1.015)^4 \):

\[ (1.015)^4 \approx 1.061364 \]

So,

\[ \text{EAR} \approx 1.061364 - 1 \]

\[ \text{EAR} \approx 0.061364 \]

To express this as a percentage, multiply by 100:

\[ \text{EAR} \approx 6.1364% \]

Therefore, the effective annual rate (EAR) is approximately 6.14%.