14111cwir8ws.1

# 14111cwir8ws.1 - 75 60 160 145 350(a What is the...

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Fall 2011 Week-in-Review #8 courtesy: Kendra Kilmer (covering Sections 7.5 and 7.6) Sections 7.5 and 7.6 If A and B are events in an experiment and P ( A ) n = 0, then the conditional probability that the event B will occur given that the event A has already occurred is P ( B | A ) = P ( A B ) P ( A ) Product Rule: P ( A B ) = P ( A ) · P ( B | A ) Tree Diagrams If A and B are independent events then P ( A | B ) = P ( A ) and P ( B | A ) = P ( B ). Futhermore, two events are independent if and only if P ( A B ) = P ( A ) · P ( B ). This can be extended to more than two events. Bayes’ Theorem 1. A survey was done of students in which both their age and the number of pieces of candy they ate on Halloween was observed. The following results were obtained: 0 1 10 > 10 Total Under 18 5 30 45 80 18 20 20 50 40 110 Over 20 25
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Unformatted text preview: 75 60 160 Total 50 155 145 350 (a) What is the probability that a student who ate 10 or fewer pieces of candy was over 20? (b) What is the probability that a student under 18 ate more than 10 pieces of candy? (c) What is the probability that a student ate 10 pieces of candy or less given they were in the age group 18 − 20? 2. If two fair six-sided dice are rolled, what is the probability that the sum is 8 given that the sum is greater than 7? 3. In one area, 4% of the population drive luxury cars. However, 17% of the CPAs drive luxury cars. Are the events “person drives a luxury car” and “person is a CPA” independent?...
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## This note was uploaded on 03/04/2012 for the course MATH 141 taught by Professor Jillzarestky during the Fall '08 term at Texas A&M.

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