Question

a survey was developed to estimate the average number of hours per week that adults spend exercising. Every third person entering a large fitness complex was surveyed with a total of 2500 people being surveyed with a total of 2500 people being surveyed. The data showed that the mesn number of hours spent exercising was 3.2hours per week.Whcih characteristic of the survey could create s bias in ghe results?

Answer 1

The survey is meant to be to find the average number of hours per week that adults spend exercising.

However, by surveying only a subset of people who are entering a fitness complex and can be presumed to be exercising much more than the general population, the mean number of hours so obtained will be much higher than that of the population. There is an undercoverage of the population here.

This bias is called a selection bias as the sample does not represent the population.