The sampling method described suffers from a form of bias. Identify the bias, tell how the sample statistic might differ significantly from the population parameter, and suggest how the problem might be corrected.An environmental group is interested in assessing the level of support amongst voters in a city for a carbon tax intended to curb carbon emissions. They survey people leaving an organic food store and find that 74% of those surveyed favor a carbon tax.

Question

What will be an ideal response?

Answer 1

There is undercoverage bias. Those shopping at an organic food store are not representative of all voters in the city as they are likely to have greater awareness of environmental issues. Support for a carbon tax is likely to be higher in this sample than amongst all voters. A more accurate estimate could be obtained by choosing a random sample from a list of the city's eligible voters.