The article \"Chances Are You Know Someone with a Tattoo, and He\'s Not a Sailor
ID: 3261510 • Letter: T
Question
The article "Chances Are You Know Someone with a Tattoo, and He's Not a Sailor" included results from a survey of adults aged 18 to 50. The accompanying data are consistent with summary values given in the article shown below. Assuming these data are representative of adults in the United States and that a U.S. adult is selected at random, use the given information to estimate the following probabilities.
(a) P(tattoo)
(b) P(tattoo | age 18Â29)
(c) P(tattoo | age 30Â50)
(d) P(age 18Â29 | tattoo)
Explanation / Answer
(a) P(tattoo) = (96+24)/(96+24+104+176) = 0.3
(b) P(tattoo | age 18-29) = 96/(96+104) = 0.48
(c) P(tattoo| age 30-50) = 24 / (24+176) = 0.12
(c) P(18 -29 |tattoo) = 96 / (96+24) = 0.80