A Random Sample of 160 Car Purchases Are Selected and Categorized

question 26

Multiple Choice

A random sample of 160 car purchases are selected and categorized by age. The results are listed below. The age distribution of drivers for the given categories is $18 \%$ for the under 26 group, $39 \%$ for the $26 - 45$ group, $31 \%$ for the $45 - 65$ group, and $12 \%$ for the group over 65 . Find the critical value $\chi _ { 0 } ^ { 2 }$ to test the claim that all ages have purchase rates proportional to their driving rates. Use $\alpha = 0.05$ .
$\begin{array}{l|cccc}\text { Age } & \text { Under 26 } & 26-45 & 46-65 & \text { Over } 65 \\\hline \text { Purchases } & 66 & 39 & 25 & 30\end{array}$

• A) \(7.815\)
• B) \(6.251\)
• C) \(11.143\)
• D) \(9.348\)

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Definitions:

Control Group

In experimental research, a group of subjects that does not receive the experimental treatment, used for comparison with the treated group.

ABAB Design

A type of experimental design in behavioral research where A represents a baseline condition and B represents an intervention or treatment, with the sequence illustrating the effect of the intervention.

Exercise Program

A planned routine of physical activities designed to improve fitness and health.

Incidence

The number of new cases of a disease or condition that are identified in a specific population during a given time period.