15 A traffic safety company publishes reports about motorcyc

15) A traffic safety company publishes reports about motorcycle fatalities and helmet use. The distribution shows the proportion of fatalities by location of injury for motorcycle accidents. The accompanying data tables show the location of injury and fatalities for 2059 riders not wearing a helmet.

(a) Does the distribution of fatal injuries for riders not wearing a helmet follow the distribution for all riders? Use the level of significance a = 0.05

Yes or No?

(b) Compare observed and expected counts for each category. What does this information tell you?

A) Wearing a helmet does not increase anybodys safety.

B) Motorcycle fatalities from head injuries occur more frequently for riders not wearing a helmet.

C) Wearing a helmet really increases the safety of a rider.

Solution

A) Wearing a helmet does not increase anybodys safety.