Final answer:
It will take Niah approximately 2.12 years to recover her investment in education.
Step-by-step explanation:
To calculate the time it will take for Niah to recover her investment, we need to compare her earnings before and after going to school.
Currently, she earns $18,000 per year as a retail sales clerk.
After completing her education in medical billing and getting a job with a median salary of $35,000, her annual earnings will increase by $35,000 - $18,000 = $17,000.
Since Niah does not work for the 2 years she is in school, her total loss of income during that time will be
$18,000 * 2 = $36,000.
Therefore, it will take Niah -
= $36,000 ÷ $17,000
= 2.12 years to recover her investment in education.