Chapter 21, Problem 4E

To determine

To explain what the study’s P-value of $0.17$ means in this context.

Explanation of Solution

It is given in the question that the researcher wants to find out have harsher penalties and ad campaign increased seat-belt use among drivers and passengers. Observations of commuter traffic failed to find evidence of a significant change compared with three years ago. Thus, the study’s P-value of $0.17$ means in this context that if harsher penalties and ad campaign have made no difference in seat-belt use, there is a $17\%$ chance of seeing an observed difference this large or larger by natural sampling variation alone.