Question

Question 2 (Essay Worth 10 points) (03.01 MC) The HR manager of a water-bottling company wants to estimate the proportion of employees that are pleased with the cleanliness of the bathrooms. She considers two methods of obtaining a sample of 550 employees from the 3,500 employees at the company. Part A: To make the process easier, the manager considers surveying the first 550 employees who enter a company's annual conference center. Identify the type of sampling method proposed and discuss why this sampling method might be biased. (5 points) Part B: The second method the HR manager is contemplating involves a stratified random sample of 550 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 bathrooms than stratification by gender? (5 points)

Answer 1

1. Sampling method is part 1 is systematic sampling. However, it will also lead to bias. Only a particular group of employees might be entering the seminar first. We are not diversifying the sample in this way.

Suppose one team in company is busy in their task and they enter seminar late. Hence entire team will be missed from the sample.

2. Stratified sampling is used when we might reasonably expect the measurement of interest to vary between the different subgroups, and we want to ensure representation from all the subgroups.

Hence if the expectation is that results would vary between campuses more than they would vary among two gender then stratification by campus is more useful.