Final answer:
The violation of a federal regulatory requirement against gender discrimination has occurred in the given scenario.
Step-by-step explanation:
The scenario described suggests a violation of the federal regulatory requirement against gender discrimination in the labor market. Gender discrimination occurs when employers pay women less than men despite having similar levels of education, experience, and expertise. In this case, the male worker is meeting and exceeding work standards while the female workers sometimes struggle to meet basic standards. However, the supervisor did not recommend a merit increase for the male worker to avoid paying him a higher wage than the female workers. This disparity in pay based on gender violates the regulatory requirement against gender discrimination.