Identify and explain a source of bias in the study described. Then suggest how the bias might have been avoided.
You plan to conduct a survey to find the percentage of people in your town who favor a new swimming pool being built at the high school. You obtain addresses from a list of property owners in the town and you mail a survey to 100 randomly selected people from the list.
◦ The list of property owners is clearly biased toward those who have children. Also, a mail survey will result in a self-selected sample. A better sampling method, such as a voluntary response survey, is needed.
◦ The list of popery owners is clearly biased toward those who can afford to own property. Also, a mail survey will result in a self-selected sample. A better sampling method, such as simple random sampling, is needed.