nationwide at selected roadway locations. Each time a motorcyclist passed by$,$ the observer noted whether the rider was wearing no helmet, a noncompliant helmet, or a compliant helmet. Using the coding

$NH=$ noncompliant helmet

$CH=$ compliant helmet

$N=no$ helmet

a few of the observations were

$CH,N,CH,NH,N,CH,CH,CH,N,N.$

There were also $796$ additional observations, which we didn't reproduce here. In total, there were $246$ riders who wore no helmet, $41$ who wore a noncompliant helmet, and $519$ who wore a compliant helmet.

The corresponding frequency distribution is given in the table below. $($Round relative frequencies to three decimal places.$)$

$\backslash$table$[[$Helmet Use Category,Frequency,Relative Frequency$],[$No helmet,,$0\mathrm{.}305$larr$246/806],[$Noncompliant helmet,$41,],[$Compliant helmet,,$],[$Total$,\backslash$table$[[806],[$uarr$],[$Total number$],[$of observations$]],\backslash$table$[[$Should total $1],[$but in some cases$],[$may be slightly off$],[$due to rounding$]]]]$