How do Americans feel about online ads tailored to their individual interests? A survey of 1,000 adult Internet users found that 55% of the 18 to 24 year olds, 59% of 25 to 34 year olds, 66% of 35 to 49 year olds, 77% of 50 to 64 year olds, and 82% of 65 to 89 year olds opposed such ads. (Data extracted from S. Clifford, "Tracked for Ads? Many Americans Say No Thanks," The New York Times, September 30, 2009, p. B3.) Suppose that the survey was based on 200 respondents in each of five age groups: 18 to 24, 25 to
34, 35 to 49, 50 to 64, and 65 to 89.
a. At the 0.05 level of significance, is there evidence of a difference among the age groups in the opposition to ads on web pages tailored to their interests?
b. Determine the p-value in (a) and interpret its meaning.
c. If appropriate, use the Marascuilo procedure and α = 0.05 to determine which age groups are different.