Super Bowl XLVI was played between the New York Giants and the New England Patriots in Indianapolis.Due to a decade-long rivalry between the Patriots and the city's own team,the Colts,most Indianapolis residents were rooting heartily for the Giants.Suppose that 90% of Indianapolis residents wanted the Giants to beat the Patriots. Refer to Exhibit 7-9.What is the probability that,of a sample of 100 Indianapolis residents,at least 15% were rooting for the Patriots in Super Bowl XLVI?
A)0.0300
B)0.0475
C)0.4763
D)0.9525

Question

Quizplus · Accepted Answer

The probability that at least 15% of the sample were rooting for the Patriots is calculated using the normal approximation to the binomial distribution. With 90% rooting for the Giants, 10% root for the Patriots. For a sample of 100, the mean is 10 and the standard deviation is 3. The z-score for 15% is 1.67, corresponding to a probability of 0.0475.

Super Bowl XLVI Was Played Between the New York Giants