In a national survey conducted by the Centers for Disease Control to determine college students’ health-risk behaviors, college students were asked, “How often do you wear a seatbelt when riding in a car driven by someone else?” The frequencies appear in the following table:

Response .....Frequency

Never ........ 125

Rarely ........ 324

Sometimes ..... 552

Most of the time ..1257

Always ........2518

(a) Construct a probability model for seatbelt use by a passenger.

(b) Would you consider it unusual to find a college student who never wears a seatbelt when riding in a car driven by someone else? Why?