The following data represent the top speed (in kilometers per hour) of all the players (except goaltenders) in the 2014 World Cup Soccer Tournament.
Speed (km/hr) Number of Players
10-13.9..........................................................4
14-17.9..........................................................7
18-21.9.........................................................17
22-25.9.........................................................91
26-29.9.......................................................282
30-33.9.......................................................206
21Find (a) the number of classes, (b) the class limits, and (c) the class width.