Question

in a national survey college students were asked, \how often do you wear a seat - belt when riding in a car driven by someone else?\ the response frequencies appear in the table to the right. (a) construct a probability model for seat - belt use by a passenger. (b) would you consider it unusual to find a college student who never wears a seat belt when riding in a car driven by someone else? (a) complete the table below. response probability never 0.024 (round to the nearest thousandth as needed.) rarely 0.075 (round to the nearest thousandth as needed.) sometimes 0.127 (round to the nearest thousandth as needed.) most of the time (round to the nearest thousandth as needed.)

Explanation:

Step1: Calculate total frequency

$108 + 338+574 + 1123+7313=9456$

Step2: Calculate probability for "Most of the time"

The frequency for "Most of the time" is $1123$. Probability $P=\frac{1123}{9456}\approx0.119$

Step3: Determine if "Never" is unusual

A probability is considered unusual if it is less than $0.05$. The probability that a student never wears a seat - belt is $0.024<0.05$, so it is unusual.

Answer:

(a)

Response	Probability
Rarely	$0.075$
Sometimes	$0.127$
Most of the time	$0.119$
Always	$\frac{7313}{9456}\approx0.774$

(b) Yes, it is unusual.