Question

what proportion of city residents uses public transportation at least once a week? city planners would like to estimate this proportion and collect information from workers entering a large office building in the center of the city. which of the following best describes the potential results of this survey?
○ this is a convenience sample and is likely to overestimate the proportion of residents who take public transportation.
○ this is a convenience sample and is likely to underestimate the proportion of residents who take public transportation.
○ this is a voluntary response sample and is likely to overestimate the proportion of satisfied residents who take public transportation.
○ this is a voluntary response sample and is likely to underestimate the proportion of satisfied residents who take public transportation.

Explanation:

1. First, identify the sampling method: Collecting from workers entering a large office building in the city center is a convenience sample (using easily accessible subjects), not voluntary response (which requires people to self - select to respond). So options with "voluntary response sample" are incorrect.
2. Then, analyze the bias: Workers in a city - center office building are more likely to use public transportation to get to work (since they are in the city center, public transport is more accessible for commuting) compared to the general city residents (which include people from all areas, some of whom may have less access to or need for public transport). So this convenience sample will likely overestimate the proportion of all city residents who use public transportation.

Answer:

A. This is a convenience sample and is likely to overestimate the proportion of residents who take public transportation.