#### Answer

a) Please see the graph.
b) 48% ride the bus
c) three times as many students ride the bus than walk.

#### Work Step by Step

a)
Total students: $252+135+432+81 = 900$
Walk: $252/900 = .28$
Bicycle: $135/900 = .15$
Bus: $432/900 = .48$
Car: $81/900 = .09$
$.28*360 = 100.8$ degrees
$.15*360 = 54$ degrees
$.48*360 = 172.8$ degrees
$.09*360 = 32.4$ degrees
c) $252/81 = 3.11$