Final answer:
The most important factor under the common-law standard for determining employment relationship is the employer's right to control the work. Skill level, while indicative of job complexity, does not define employment status.
Step-by-step explanation:
When FedCo Staffing is considering whether to hire Julie Smith as an independent contractor or an employee under the common-law standard, the most important factor is not the worker's level of skill, hours of work, or method of payment, but the right to control the work. This includes the right to direct and control the manner and means by which the work is accomplished. While the level of skill can influence the complexity and importance of a position, it does not solely determine the nature of the employment relationship.