To solve this, we are going to use the compound interest formula:

where

is the final amount after

years
tex]P[/tex] is the initial investment

is the interest rate in decimal form

is the number of times the interest is compounded per year

is the time in years
We know form our problem that the initial invest is <span>$30,000 and the period is ten years, so </span>

and

. We also know that the interest is compounded one time per year, so

. To convert the interest rate to decimal form, we are going to divide the rate by 100%


Lets replace the values in our formula:



Replacing

with

:
We can conclude that the correct answer is D. 
Now, to find <span>much Yolanda will have after 10 years, we just need to perform the operations in our equation:
</span>


We can conclude that Yolanda will have $64,170.54 in her account after ten years of earning <span>
a compound interest rate of 7.9% per year.</span>