Question

You want to do a survey on how religious people are in your town. what do you need to have a valid scientific sample? check all that apply.

Answer 1

I believe the answer is:

random sample of the town's population

A mix of participants that reflect your town's makeup

Random sample is needed in order to ensure that the researchers do not obtain only the subjects that is close to them. Mix of participants is needed in order to ensure that the sample population are not taken from group with close similarties in behaviour.