Its my last question im almost done a researcher posts a newspaper advertisement offering $10 in exchange for participation in a short study. the researcher accepts the first 10 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 is offered to participants. it is a valid sample because the first 10 people were selected to participate. it is not a valid sample because it is not a random sample of the population.