Answer:
8.85% per year
Step-by-step explanation:
To find the interest rate of a compounding interest, we use the formula:
[tex]r=n[(\dfrac{A}{P})^{\dfrac{1}{nt}}-1][/tex]
Before we start solving, let's break down all the variables that we have.
A = 19,992.71
P = 10,000.00
n = 2
t = 8
r = ?
Now let's put the values into the formula.
[tex]r=2[(\dfrac{19,992.71}{10,000.00})^{\dfrac{1}{2(8)}}-1][/tex]
[tex]r=2[(\dfrac{19,992.71}{10,000.00})^{\dfrac{1}{16}}-1][/tex]
[tex]r=2[(\dfrac{19,992.71}{10,000.00})^{0.0625}-1][/tex]
[tex]r=2[(1.9992.1)^{0.0625}-1][/tex]
[tex]r=2[1.0442499885-1][/tex]
[tex]r=2[0.0442499885][/tex]
[tex]r=0.08849997699[/tex] or [tex]8.85%[/tex]
So the rate the Mrs. Emily Francis got from the bank was 8.85% per year.
