Chi-square test for independence of attributes.
Injuries and Motorcycle Helmet Colour A case-control (or retrospective) study was conducted to investigate a relationship between the colours of helmets worn by motorcycle drivers and whether they are injured or killed in a crash. Results are given in the table below. Test the claim that injuries are independent of helmet colour. Should motorcycle drivers choose helmets with a particular colour? If so, which colour appear bets?
|
Colour of Helmet
|
|
|
White
|
Black
|
Yellow/Orange
|
Red
|
Blue
|
|
Controls(Not Injured)
|
337
|
419
|
31
|
170
|
55
|
|
Cases(Injured or Killed)
|
112
|
213
|
8
|
70
|
26
|