1.The leader of a city crime watch team sends out a survey to her neighbors asking them to vote on the best time to patrol the city to watch for criminal acts. Describe how the design of the survey leads to bias.

a.A nonresponse error was made in this design. This type of sampling only represents the city and not the entire county population.

b.A nonresponse error was made in this design. This type of

sampling only represents the neighborhood with the worst crime and not the

entire city population.

c.A convenience sample error was made in this design. This type of

sampling only represents the neighborhood with the least crime and not the

entire city population.

d.A convenience sample error was made in this design. This

type of sampling is only representative of one neighborhood and not the entire

city population.

e.There are no potential areas of bias.

2.A study was conducted on the effect of daytime running lights on cars. Researchers gathered data from a random sample of 3,248 drivers and measured quite a few variables, in addition to the explanatory variable of daytime running lights and the response variable of less accidents. According to a newspaper article summarizing the study, those cars that had daytime running lights were more likely to be operated by drivers who were confident and attentive. Drivers whose cars did not have daytime running lights were about 22% more likely to have an accident. What conclusion can we draw from this study? Explain.

a.We can infer a cause-and-effect relationship because the sample was selected randomly.

b.We cannot infer a cause-and-effect relationship because we do not have a control group.

c.We can infer a cause-and-effect relationship because multiple variables were d. included.

d.We cannot infer a cause-and-effect relationship because treatments were not assigned.

e.We cannot infer a cause-and-effect relationship because the treatments imposed were not blocked correctly.