5.74 Independent on coffee? Students in a geography class are asked whether they’ve visited Europe in the past 12 months and whether they’ve flown on a plane in the past 12 months.

a. For a randomly selected student, would you expect these events to be independent or dependent? Explain.

b. How would you explain to someone who has never studied statistics what it means for these events to be either independent or dependent?

c. Students in a different class were asked whether they’ve visited Italy in the past 12 months and whether they’ve visited France in the past 12 months. For a randomly selected student, would you expect these events to be independent or dependent? Explain.

d. Students in yet another class were asked whether they’ve been to a zoo in the past 12 months and whether they drink coffee. For a randomly selected student, would you expect these events to be independent or dependent? Explain.

e. If you had to rank the pairs of events in parts

a, c, and d in terms of the strength of any dependence, which pair of events is most dependent? Least dependent?