A survey showed that 8% of Internet users age 18 and older report keeping a blog. Referring to the 18-29 age group as young adults, the survey showed that for bloggers 54% are young adults and for nonbloggers 24% are young adults (Pew Internet & American Life Project, July 19, 2006).
a. Develop a joint probability table for these data with two rows (bloggers vs. non-bloggers) and two columns (young adults vs. older adults).
b. What is the probability that an Internet user is a young adult?
c. What is the probability that an Internet user keeps a blog and is a young adult?
d. Suppose that in a follow-up phone survey we contact someone who is 24 years old.
What is the probability that this person keeps a blog?