Example 2.17 Of the voters in a city, 40% are Republicans and 60% are Democrats. Among the Republicans 70% are in favor of a bond issue, whereas 80% of the Democrats favor the issue. If a voter is selected at random in the city, what is the probability that he or she favor the bond issue?

Ponderosa Paint and Glass carries three brands of paint. A customer wants to buy another gallon of paint to match paint she purchased at the store previously. She can’t recall the brand name and does not wish to return home to find the old can of paint. So, she selects two of the three brands of paint at random and buys them. What is the probability that she matched the paint brand? Her husband also goes to the paint store and fails to remember what brand to buy. So, he also purchases two of the three brands of paint at random. Determine the probability that both the woman and her husband fail to get the correct brand of paint. (Hint: Are the husband’s selections independent of the wife’s selections?)

Suppose two companies, Company A and Company B, produce all the widgets in Ottawa. Company A produces 70% of all the widgets in Ottawa. 20% of widgets produced by Company A are defective. 10% of widgets produced by Company B are defective. If a widget is chosen at random, what is the probability it is defective? Select one: a. 0.07 b. 0.17 c. 0.13 d. 0.03 e. 0.14

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