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Survey Problems MATH 102 Contemporary Math S. Rook Overview • Section 2.4 in the textbook: – Survey problems Survey Problems Survey Problems • Essentially we are using previous set techniques to solve word problems involving surveys, polls, and reports – Cardinal number is an important concept • Drawing a Venn Diagram is invaluable when solving a survey problem • MUST practice to master! Survey Problems (Example) Ex 1: Find the number of elements in the desired sets using the given information: a) n A B 25, n A B 7, n A'B 11 ; n(A), n(B) nB C 4, nC B 9, n A B C 3, nB C 22, b) n A C 7, n A B 7, n A C 5 n(A), n(B), n(C) Survey Problems (Example) Ex 2: See exercise 44 on page 71 of the textbook. Survey Problems (Example) Ex 3: Consider the following table representing voting information on a proposition in the last school election. a) c) Freshmen (F) Sophmores (So) Juniors (J) Seniors (Sr) Total Yes (Y) 700 300 50 15 1065 No (N) 200 100 175 100 575 Did not Vote (DNV) 100 100 25 10 235 Total 1000 500 250 125 1875 nF N nSo Y b) nDNV J Sr d) nJ ' Sr N ' Survey Problems (Example) Ex 4: Suppose a Nielsen ratings report states the following information: 6 million people watched the season finale of NCIS, 3 million people watches the season finale of Burn Notice, 1 million watch both, and 8 million watched only one of the season finales. How is this information inconsistent? Summary • After studying these slides, you should know how to do the following: – Solve survey problems using set theory • Additional Practice: – See the list of suggested problems for 2.4 • Next Lesson: – Statements, Connectives, & Quantifiers (Section 3.1)