A city planner wants to learn about the factors that affect whether people walk or bike to work. She collects data from a random sample of 500 employed people who reside in her city. She wants to examine the effects of overall health and proximity of residence to work on the number of days that people bike or walk to work per year.

a. Assuming that people’s decisions about where to live in relation to their work are unaffected by their physical health, draw the appropriate visual representation of the relationship among these three variables. Explain why this is the appropriate way to model the relationship.

b. Tables 13.24, 13.25, and 13.26 show three different components of the relationship among these variables. Is there a relationship between physical health and walking to work? Which table(s) can you use to answer this question?

c. Is there a relationship between proximity of residence to work and walking/

biking to work? Which table(s) can you use to answer this question?

d. Describe the relative effects of physical health and proximity of residence to work on the number of days that people walk or bike to work, on average.

e. The city planner wants more people to walk and bike to work. She looks at the results in these tables and concludes that, in order to increase the number of bike and pedestrian commuters, building affordable housing close to the business district where many of the city’s residents work is a better use of city money than launching a health initiative. Do you agree? Explain your answer.