Over 221 million computer and video games were sold in 2002—nearly two games for every U.S. household according to the Detroit News (February 15, 2004). Of Americans age 6 or older 60%—about 145 million people—play computer and video games. 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