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Name: ____________________________________4D Practice – Conditional Probability and Independence2708910276225001.Finger length and gender Is there a relationship between gender and relative finger length? To find out, we randomly selected 452 U.S. high school students who completed a survey. The two-way table summarizes the relationship between gender and which finger was longer on the left hand (index finger or ring finger). Suppose we randomly select one of the survey respondents. Define events R: ring finger longer and F: female.a) Find P(R | F). Interpret this value in context.b) Given that the chosen student does not have a longer ring finger, what’s the probability that this person is male? Write your answer as a probability statement using correct symbols for the events.2675890367030002.Third-class passengers The Titanic struck an iceberg and sank on its first voyage across the Atlantic in 1912. Some passengers got off the ship in lifeboats, but many died. The two-way table gives information about adult passengers who survived and who died, by class of travel. Suppose we randomly select one of the adult passengers who rode on the Titanic.a) Given that the person selected was in first class, what’s the probability that he or she survived?b) If the person selected survived, what’s the probability that he or she was not a third-class passenger?c) Are the events “Survived” and “First class” independent? Justify your answer.435292503.Homeowner education What is the relationship between educational achievement and home ownership? A random sample of 500 U.S. adults was selected. Each member of the sample was identified as a high school graduate (or not) and as a homeowner (or not). Define event G as being a high school graduate and event H as being a homeowner. The Venn diagram summarizes the data based on these two events. What’s the probability that a randomly selected person who owns a home is also a high school graduate? 4.140 characters A 2014 survey suggests that 71% of U.S. teenagers use Facebook, 33% use Twitter, and 15% do both. Suppose we select a U.S. teenager at random and learn that the student uses Facebook. Find the probability that the student uses Twitter.5.Mac grads? A recent census at a major university revealed that 60% of its students mainly used Macs. The rest primarily used PCs. At the time of the census, 67% of the school’s students were undergraduates. The rest were graduate students. In the census, 23% of respondents were graduate students who said that they used Macs as their primary computers. Suppose we select a student at random from among those who were part of the census and learn that the student mainly uses a Mac. Find the probability that this person is a graduate student.6.Give me a hand The 28 students in Mr. Tabor’s statistics class completed a brief survey. One of the questions asked whether each student was right-or left-handed. The two-way table summarizes the class data. Choose a student from the class at random. Are the events “female” and “righthanded” independent? Justify your answer. ................
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