More than 272 million computer and video games were sold in 2010—more than two games for every U.S. household. Gamers spend an average of 3 to 4 hours playing games online every day. The average age of players is 28. Video games and gamers have even created a new form of marketing—called “advergaming.” “Advergaming is taking games—something that people do for recreation—and inserting a message,” said Julie Roehm, director of marketing communications for the Chrysler Group, which sells Chrysler, Jeep, and Dodge brand vehicles. “It’s important we go to all the places our consumers are.” Suppose it is possible to assume the standard deviation of the ages of video game users is 9 years and that the distribution is bell shaped. To assist the marketing department in obtaining demographics to increase sales, determine the proportion of players who are
a. between 19 and 28
b. between 28 and 37
c. older than 37