Question: Sample Selection Methods. You are employed by Fish Wrap Ltd., a local newspaper distribution company, and are attempting to determine the average level of customer satisfaction with the newspaper's delivery service. All customers are included in a comprehensive database that includes the following information: customer name, delivery address, telephone number, type of service (weekly only, weekend only, weekly/weekend), length of service (how long they have subscribed to the newspaper), and name of carrier. Because the local area has 10,500 subscribers, Fish Wrap has decided to sample its customers instead of surveying the entire population. Based on a number of factors (including precision and reliability), Fish Wrap has determined that a sample of 150 customers is necessary.
Required: a. In this application, what are some of the major characteristics of subscribers that should be considered to ensure that a representative sample is selected?
b. Identify and briefly define four major methods used to select a sample.
c. How could you select a sample from the population using each of these methods?
d. The information in each list is arranged in descending order based on length of service. Indicate how each of the following factors could impact your ability to use the four methods of selecting a sample from a population:
1. The database is a typed list of information.
2. The database is an electronic list of information and cannot be sorted on any other characteristic.
3. The database is an electronic list of information and can be sorted on any characteristic.
e. How does each of the following factors impact your ability to evaluate whether you have selected a representative sample from the population?
1. Delivery address does not include zip code or other reasonable way of identifying physical location within the subscription area.
2. The length of service is classified as follows: less than six months, six months to one year, more than one year.
3. If customers have relocated within the subscription area, their length of service has been reset to zero even when they continued their subscriptions.