A large retail company has 500 stores in the United States and 300 stores in Europe. The average number of employees per store is 200, for a total of 100,000 employees in the United States and 60,000 employees in Europe.. The company is considering offering employees one of the two benefits--one additional day of paid vacation per year or a small increase in pay. A survey will be given to a sample of employees to investigate which benefit is preferred and whether there is a difference in preference between employees in United States and Europe.

Two sampling methods are

Sampling Method 1: The company will randomly select 8 stores from 800 stores. All employees from 8 selected stores will be asked which benefit they prefer.

Sampling Method 2: The company will randomly select 1000 employees from the list of all the employees in United States stores and 600 employees from a list of all employees in Europe stores. All 1600 selected employees will be asked which benefit they prefer.

a) One of the two methods results in a stratified sample of employees and the other results in a cluster sample of employees.

Identify the sampling method that results in a stratified sample of employees, and identify the strata.
Identify the sampling method that results in a cluster sample of employees, and identify the clusters.
b) Give one statistical advantage and one statistical disadvantage of using sampling method l .

c) Explain a statistical advantage of using sampling method 2 rather than using a simple random sample