Question

Running red lights The sample described in Exercise $31$produced a list of $5024$licensed drivers. The investigators then chose an SRS of $880$ of these drivers to answer questions about their driving habits. One question asked was: “Recalling the last ten traffic lights you drove through, how many of them were red when you entered the intersections?” Of the $880$ respondents, $171$admitted that at least one light had been red. A practical problem with this survey is that people may not give truthful answers. What is the likely direction of the bias: do you think more or fewer than $171$ of the $880$ respondents really ran a red light? Why?

Short answer

We expect more than $171$ respondents to admit that they ran a red light.

Step-by-step solution

Given information

A sample size of drivers, $n=880$

A practical problem with this survey is that people may not give truthful answers.

Concept

A simple random sample (SRS) of size $n$ is made up of $n$ people chosen from the population with an equal chance of being the sample that is actually chosen.

Explanation

There could have been a large number of persons that ran a red light. However, due to societal difficulties, most will not admit to running a red light. As a result, we predict more than $171$ people to admit to running a red light.