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Leah is flying from Boston to Denver with a connection in Chicago. The probability her first
flight leaves on time is 0.15. If the flight is on time, the probability that her luggage will make
the connecting flight is 0.95, but if the first flight is delayed, the probability that the luggage
will make it is only 0.65.
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2. Suppose that 23% of adults smoke cigarettes. It's known that 57Yo of smokers and 13% of nonsmokers develop a certain lung condition by the age of 60.
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What is the probability that a randomly selected 60-year-old has this lung condition? > < :i< ,i;ÿ
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The probability of having a certain disease is .05. The probability of testing positive if you
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have the disease is .98; the probability of testing positive when you do not have the disease is
.10. Use a tree diagram to answer the following:
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What is the probability that you will test positive for the disease given that you actually have
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What is the probability that you won't test positive for the disease given that you have it? 0,(3ÿp ,
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Find all of the joint probabilities, then find the probability of not testing positive for the
disease.
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Let A = {student studies} with P(A) = .5 and let B = {student does well on a test}. Also, let the
following be true:
P(Student studies and does well on a test) = .35
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P(Student studies and does poorly on a test)
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P(Student doesn't study and does well on a test) = .05
P(Student doesn't study and does poorly on a test) = .45
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What is +he probability that a student does poorly', given that he/she didn't study?
What is the probability that a_D_y student does well?
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Binge drinking on college campuses. B nge drinking is 4 or more drinks in a row.
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445'o of the college students binge drink, 37% drink moderately and 19% abstain from drinking.
Among binge drinkers aged 21-34 17% have been involved in an alcohol related auto accident
and 9% of non binge drinkers have been in an alcohol related auto accident. Find the
probability that a randomly selected college student will be a binge drinker if they had an
alcohol-related auto accident.
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After surveying 995 adults, 81.5% of who were over 30, the National Sleep Foundation reported
that 38.8% of all adults snored. 32% of the respondents wereisnorers over the age of 30ÿ "
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Is snoring independent of age? Explain.
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