Where people turn for news is different for various age groups. (Data extracted from "Cellphone Users Who Access News on Their Phones," USA Today, March 1, 2010, p. 1A.) A study was conducted on the use of cell phones for accessing news. The study reported that 47% of users under age 50 and 15% of users age 50 and over accessed news on their cell phones. Suppose that the survey consisted of 1,000 users under age 50, of whom 470 accessed news on their cell phones, and 891 users age 50 and over, of whom 134 accessed news on their cell phones.
a. Is there evidence of a significant difference in the proportion of users under age 50 and users 50 years and older that accessed the news on their cell phones? (Use α = 0.05.)
b. Determine the p-value in (a) and interpret its meaning.
c. Construct and interpret a 95% confidence interval estimate for the difference between the population proportion of users under 50 years old and those 50 years or older who access the news on their cell phones.