The CEO of a local tech company wants to estimate the proportion of employees that are pleased with the cleanliness of the breakrooms. She considers two methods of obtaining a sample of 600 employees from the 4,700 employees at the company.

Part A: To make the process easier, the CEO considers surveying the first 600 employees who enter a company annual conference center. Identify the type of sampling method proposed and discuss why this sampling method might be biased.

Part B: The second method the CEO is contemplating involves a stratified random sample of 600 employees. The company has two campuses with male and female employees at each campus. What circumstances would stratification by campus give a more precise approximation of the proportion of employees who are satisfied with the cleanliness of the breakrooms than stratification by gender?