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# Problem 2

3.7 Probability of At Least One

The following report is from a researcher at the University of Chicago.  Laumann and co-researcher Dr. Amy Derick, of the University of Chicago, found that year of birth was a predictive factor for tattoos: 36 percent of people aged 18 to 29; 24 percent of those aged 30 to 40; and only 15 percent of those aged 40 to 50 had tattoos.  Sixteen percent had obtained their first tattoo before age 18.  People of lower educational status were more likely to have a tattoo and also more likely to have more than one tattoo than those of higher educational status.  Drinking alcohol and using recreational drugs were related to having tattoos. Over a third of ex-drinkers and a fourth of current drinkers had tattoos, as did almost 40 percent of those who have ever used recreational drugs and 60 percent of those who have been in jail for more than three days.  Tattoos were seen in all ethnic groups but were more common among those with Hispanic ancestry than among all other ethnic groups combined... What is the probability that among 10 randomly selected people aged 30 to 40 at least 1 of them has a tattoo?