Question:

In a recent election, a local news outlet conducted an opinion poll to gauge public sentiment towards the mayoral candidates. The news outlet randomly selected 500 registered voters from a database of 10,000 voters in the city. The poll showed that 60% of the respondents favored candidate A. Based on this information, answer the following questions:

a) What is the population in this context? b) What is the sample in this context? c) Explain the concept of random sampling. d) Identify three potential sources of bias that could affect the accuracy of the poll results. e) How reliable are the findings of this opinion poll? Explain your answer.

Answer:

a) The population in this context refers to all registered voters in the city, which totals 10,000.

b) The sample in this context refers to the 500 registered voters selected by the news outlet for the opinion poll.

c) Random sampling is a method of selecting a sample from a population in a way that each individual has an equal chance of being chosen. It helps to minimize bias and ensure that the sample represents the population as accurately as possible. In this case, the news outlet randomly selected 500 registered voters from the database of 10,000 voters, increasing the likelihood of obtaining a representative sample.

d) Three potential sources of bias that could affect the accuracy of the poll results are:

1. Selection bias: If the news outlet only selected voters from certain neighborhoods or demographics, it may not represent the diversity of the population accurately. For example, if the poll only includes affluent neighborhoods, it could skew the results in favor of a particular candidate.
2. Measurement bias: The poll questions or methodology may introduce bias if they are worded in a way that favors a particular candidate or if the surveyors display any form of influence during the data collection process.
3. Non-response bias: If a large number of selected voters decline to participate in the poll or cannot be reached, it may introduce bias as those who choose not to respond may have different opinions than those who do respond.

e) The reliability of the findings of this opinion poll depends on several factors. Firstly, the random sampling method used increases the chances of getting a representative sample. However, the relatively small sample size of 500 out of a population of 10,000 may still introduce some margin of error. Additionally, the potential sources of bias identified, such as selection bias and non-response bias, could compromise the accuracy of the results.

To determine the reliability of the findings more accurately, it would be necessary to assess the methodology of the poll in more detail, including the wording of the questions, the demographics of the respondents, and the potential sources of bias. Conducting the poll with a larger sample size and minimizing non-response bias by reaching out to a higher percentage of selected voters could also enhance the reliability of the findings.