(Quiz 240 ) Stratified Sampling: The owner of a private food store is concerned about
employee morale. She decides to survey the mangers and hourly employees to see if she can
learn about work environment and job satisfaction. From the list of workers at the store,
obtain a stratified sample of three manages and five hourly employees to survey. (Use
There is no list available.
Stratified sampling is a sampling technique where the population is divided into different strata or groups based on specific characteristics, and then a sample is taken from each stratum. This ensures that the sample accurately represents the different groups within the population and can provide more precise results.
In this case, the owner of the private food store wants to survey both the managers and the hourly employees to gather information about the work environment and job satisfaction. To obtain a stratified sample, you need to divide the workers into two strata: managers and hourly employees.
Here's how you can obtain a stratified sample of three managers and five hourly employees:
1. Obtain the list of workers at the store: Start by obtaining a comprehensive list of all the workers employed at the store, including both managers and hourly employees.
2. Divide the workers into strata: Based on their job titles, divide the workers into two groups: managers and hourly employees. Ensure that every worker is classified correctly into the appropriate stratum.
3. Determine the sample size: Decide on the desired sample size for each stratum. The owner wants to survey three managers and five hourly employees.
4. Randomly select samples from each stratum: Use a random sampling method to select the desired number of workers from each stratum. This can be done using a random number generator or by assigning each worker a number and selecting the corresponding numbers randomly.
For example, if you have 10 managers and 20 hourly employees on the list:
- Managers (Stratum 1):
- Randomly select three managers from the total pool of managers. This can be done by assigning each manager a number from 1 to 10 and selecting three random numbers between 1 and 10.
- Hourly Employees (Stratum 2):
- Randomly select five hourly employees from the total pool of hourly employees. This can be done by assigning each hourly employee a number from 1 to 20 and selecting five random numbers between 1 and 20.
Remember, the key is to ensure that the samples represent the characteristics of each stratum proportionally. This means that the sample size should be representative of the proportion of managers to hourly employees in the total population.
Once you have selected your stratified sample, you can then proceed with surveying these individuals to gather information about work environment and job satisfaction.