Final answer:
To determine Joanie's earnings, the 4% commission rate is applied to her total sales of $15,000, resulting in earnings of $600.
Step-by-step explanation:
Joanie earns a commission based on her sales of electronics. To calculate her earnings, we need to apply the 4% commission rate to her total sales of $15,000 worth of electronics.
The formula to find her earnings is:
Commission = Total Sales × Commission Rate
Therefore, Joanie's earnings would be:
Commission = $15,000 × 0.04
Commission = $600
So, Joanie's earnings from her sales would be $600.