A business developer would like to purchase an abandoned corner lot in a small town and build a small convenience store with gasoline pumps on the site. Town leaders are concerned about potential traffic and noise impact to the adjacent neighborhood and send printed surveys to 500 homes in the affected area. Of the 123 surveys returned, 87% oppose the plan to develop the corner lot. How could the sampling design cause town leaders to overestimate or underestimate overall support of the development plan?
Some government leaders propose allowing oil companies to drill in currently protected lands that may be rich in oil reserves. Environmental researchers argue that drilling in such lands would be harmful to the surrounding ecosystem. To measure support for drilling in such lands, an oil company representative uses random-digit telephone dialing to contact adults in the region and measure opinion for increased drilling. One question in the survey asks, "Given that an increase in drilling could result in increased tax revenue and additional jobs to the region, would you support a proposal to allow drilling in lands currently protected from drilling?” What type of bias could be most likely affecting the survey results?
Many large cities use taxes on entertainment tickets to pay for improvements to public facilities, like stadiums, arenas, and concert venues. A city council proposal would increase the current ticket tax in order to raise funds for a new public concert hall. Council representatives plan to conduct a survey outside of a large concert in the summer and ask selected adults if they would support an increase in the ticket tax to pay for the new concert hall. Which type of bias will most likely affect the survey results?
A large retirement community provides many activities for its residents. The activity director is considering adding a trivia night on Tuesday evenings if there is enough interest from the residents. To measure interest in the trivia night, the activity director leaves a printed survey in residents’ mailboxes, on which the resident can express whether they are interested. Of the 68 surveys returned, 55 expressed interest. Which of these describes the type of bias in this survey and a likely direction of the bias in estimating overall community support for the trivia night?
A restaurant chain would like to measure the proportion of customers who are generally satisfied with the service provided by its staff. At the end of the meal, as the check is delivered to the table, the server asks those at the table to rate their satisfaction with the service provided as "Very Satisfied,” "Satisfied,” or "Not Satisfied.” During a one-week period, 147 customers were surveyed and 135 (93%) reported they were either Satisfied or Very Satisfied. What type of bias may be present in the survey results?
A team of community members hopes to use land in a current empty lot for a dog park. To determine if the community generally approves of the use of the lot for a dog park, volunteers survey shoppers leaving a pet store located near the lot. The results show that 83% of the 112 people surveyed approve of the dog park plan. How might the survey results be biased in estimating community support for a dog park?
Many large cities have considered or passed proposals that ban the use of plastic grocery bags in stores. A concerned student would like to measure if residents of her hometown would consider a similar ban on plastic bags. Standing in a busy shopping area, the student approaches adults and asks, "Items made of plastics are a dangerous, growing source of pollution to our world’s oceans and threaten many animal species. Given this, would you support a ban on plastic shopping bags in our city stores?” How might the results of this survey be biased in estimating the proportion of all town residents who would support a ban on plastic bags?
A restaurant chain would like to measure the proportion of customers who are generally satisfied with the service provided by its staff. At the end of the meal, as the check is delivered to the table, the server asks those at the table to rate their satisfaction with the service provided as "Very Satisfied,” "Satisfied,” or "Not Satisfied.” During a one-week period, 147 customers were surveyed and 135 (93%) reported they were either Satisfied or Very Satisfied. What type of bias may be present in the survey results?
To ease congestion in a downtown area, city planners are considering a plan to widen a major thoroughfare from two driving lanes to three driving lanes. This plan would require closing a section of downtown streets as the work begins. In order to assess public support for the plan, city planners provided a phone number to residents that could be used to register opinion for or against the plan. In total, 267 calls were received, with only 24% supporting it. Which statement describes the most likely type of bias in this setting?
Many adults owe money from their college loans for years into their professional careers. A newspaper would like to estimate the proportion of all adults in the city who have debts from college loans. To collect data, a random sample of 300 young adults between the ages of 25 and 35 is asked, "Do you have more than $5,000 in current college debts?” 68% of those sampled reported that they do have more than $5,000 in college-related debts. How might this sample be biased in obtaining an estimate of all adults in the city who have college debts?
Did you find these answers helpful?