Question

Running red lights An SRS of 880 drivers was asked: “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. Explain

the likely direction of the bias.

Short answer

The directions of this bias will be towards higher side as most people will not want to admit to driving through a red light and thus the proportion is likely higher.

Step-by-step solution

Given information

We need to explain the likely direction of the bias.

Explanation

Because most individuals are reluctant to admit to running a red light, the percentage is likely to be greater, implying that more than $171$respondents have done so.

These causes of bias are not sampling error, and the margin of error only covers sampling error, hence they have been excluded from the margin of error.