Over a period of a few years the population of Denver increased It was observed that during this period the correlation between the number of people attending church and the number of people receiving traffic tickets was r 0 92 Does going to church cause people to get traffic tickets Is there a lurking variable that might cause both variables to increase O Going to church causes people to get traffic tickets O Getting traffic tickets causes people to go to church The increase in population is a lurking variable that caused both variables to increase