Question

1. a local television station takes quick polls of public opinion by announcing a question on the 6 oclock news and asking viewers to call - in or text their opinion of “yes” or “no” to the station. the results are announced on the 11 oclock news. one such poll finds that 73% of those who called in or texted are opposed to a proposed local gun control ordinance.

a. what do you think the population is in this situation?
b. explain why this sampling method is biased. is the percent of the population who oppose gun control probably higher or lower than the 73% of the sample who are opposed?

1. a big - city police department wants to know how african - american residents of the city feel about police service. they prepare a questionnaire with several questions about the police. a sample of 300 mailing addresses in predominantly african - american neighborhoods is chosen, and a police officer is sent to each address to administer the questionnaire to an adult living there. do you think that this sample survey will produce trustworthy information? why or why not?

Explanation:

9. a.

The population is all the viewers of the local television station.

This sampling method is biased because it only includes those viewers who are motivated enough to call - in or text. People with strong opinions (either for or against) are more likely to participate. Since 73% is from a self - selected sample (those who called or texted), the actual percent of the population who oppose gun control is probably lower. People who are opposed may be more likely to take the time to call or text compared to those who are in favor or neutral.

This sample survey will not produce trustworthy information. The sample is not representative of all African - American residents of the city. Just sampling from predominantly African - American neighborhoods does not account for all African - American residents (e.g., those who may have moved out of these neighborhoods but still identify as African - American, or those with different socioeconomic statuses within the neighborhoods). Also, having a police officer administer the questionnaire may introduce response bias. African - American residents may be less likely to give their true opinions to a police officer due to past experiences or mistrust.

Answer:

All the viewers of the local television station.

9. b.