The expression 1,000(1.0215)4t represents the amount of money in an account after t years.


The interest is compounded [annually/semiannually/quarterly/monthly], and the effective annual interest rate on the account is [2.15%/4.00%/8.60%/8.88%].


What are the two correct answers that complete the sentences? Choose from the brackets above.

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Answer:

The interest is compounded quarterly.

The effective annual interest rate on the account is 8.60%.

Step-by-step explanation:

Compound interest:

The compound interest formula is given by:

[tex]A(t) = P(1 + \frac{r}{n})^{nt}[/tex]

Where A(t) is the amount of money after t years, P is the principal(the initial sum of money), r is the interest rate(as a decimal value), n is the number of times that interest is compounded per unit year and t is the time in years for which the money is invested or borrowed.

We are given:

[tex]A(t) = 1000(1.0215)^{4t}[/tex]

Comparing to the general formula.

[tex]P = 1000[/tex]

[tex]1 + \frac{r}{n} = 1.0215[/tex]

[tex]nt = 4t[/tex]

From the last one:

[tex]n = 4[/tex]

Which means 4 compoundings per year. This means that the interest is compounded quarterly.

Interest rate:

[tex]1 + \frac{r}{n} = 1.0215[/tex]

Since n = 4.

[tex]\frac{r}{4} = 1.0215 - 1[/tex]

[tex]\frac{r}{4} = 0.0215[/tex]

[tex]r = 4*0.0215[/tex]

[tex]r = 0.0860[/tex]

So the interest rate is of 8.60%.

Answer:

the answer is quarterly and 8.88

Step-by-step explanation:

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