[kevkrom]

That's a valid method when the sample is randomly selected and sizable - neither of which was the case here.

Don't forget that the sample needs to be representative as well.

[ConservingFreedom]

That's a valid method when the sample is randomly selected and sizable - neither of which was the case here.

Don't forget that the sample needs to be representative as well.

If it's truly random and big enough, it's representative (although simple random sampling doesn't get you to "big enough" as quickly as stratified random smapling).