Final answer:
Supervisors in a fast-food restaurant can be of varying ages, typically starting from 22 years old, but can sometimes be younger due to the industry's high turnover rates and opportunities for rapid advancement.
Step-by-step explanation:
The age of Robert's supervisor in a restaurant setting can vary widely and is contingent on a variety of factors such as the specific job requirements, company policies, and labor laws. Typically, supervisors are required to have some level of managerial experience or training, which usually means they are a bit older than entry-level employees. It is common to find supervisors in the age range of 22-25, as they are likely to have obtained a few years of experience. However, depending on the restaurant's structure and the supervisor's career progression, they could also be in the 30-35 or 40-45 age ranges. It is less common, though not unheard of, for someone as young as 18-21 to be a supervisor, particularly in a fast-food restaurant environment where younger individuals may be promoted due to high employee turnover rates or outstanding performance.