help please!

Question

An Internet service provider (ISP) conducts an anonymous survey of its subscribers and 2500 of them respond by reporting the values of the cars that they currently own. Given that the sample size is so large, think about the following:

1. Are the results likely to result in a mean that is fairly close to the mean value of all cars owned by Americans?
2. Why or Why not?

Answer 1

Probably not because this may not be a representative sample of all car-owners. There could be a response bias in that the ones who responded may have shared a common feature that prompted them to respond, and this feature may correlate with the value of the cars they own. Results from voluntary responses must be interpreted with caution.