Question

PLEASE HELP
A researcher posts a newspaper advertisement offering $20 in exchange for participation in a short study. The researcher accepts the first five people who respond to the advertisement. Which of the following statements is true about the sample?

It is not a valid sample because it is only a short study.
It is a valid sample because money was offered to participants.
It is a valid sample because the first five people were selected to participate.
It is not a valid sample because it is not a random sample of the population.

Answer 1

When you're doing an experiment/observational study, you need to have a random sample of the population. The first five people who respond to the advertisement don't represent the entirety of the people

Answer 2

Im confused?

Answer 3

so what is the answer?

Answer 4

Well, first, of what I said, do you think it's a valid sample or an invalid sample

Answer 5

no

Answer 6

It's an invalid sample-
and then we choose between
It is a valid sample because money was offered to participants.
It is a valid sample because the first five people were selected to participate.

One point I'd like to make is that choosing the first five people that responded isn't 'random' enough, it doesn't represent the whole population

Answer 7

From there, I think that you can get the answer