Final answer:
The commission rate of the salesperson is calculated by dividing the commission earned by the total sales amount and then converting it to a percentage. In this case, it is approximately 13.85%.
Step-by-step explanation:
To find the commission rate, we divide the commission the salesperson earns by the total amount of merchandise sold. The formula for the commission rate is commission rate = (commission ÷ sales) × 100%.
In this case, the commission is $360 and the total sales amount is $2600.
Commission rate = ($360 ÷ $2600) × 100%
= 0.1384615385 × 100%
≈ 13.85%
Therefore, the salesperson's commission rate is approximately 13.85%.