2.9 In a recent survey of people aged 50-71 in the United States summarized by N.

Freedman et al. (Lancet Oncol. 9: 649-656, 2008), during a follow-up period the annual probability of lung cancer occurrence was about 0.00023 for people who had never smoked and about 0.01284 for current smokers who smoked more than two packs per day. Find and interpret the difference of proportions and the relative risk.

Which measure is more informative for these data? Why?