It is easy to suggest that a bigger sample is more representative of a population than a smaller sample. Is this always true? Design an experiment to study the relationship between class attendance and exam grades? Which sampling method is most appropriat

It is easy to suggest that a bigger sample is more representative of a population than a smaller sample. Is this always true? Design an experiment to study the relationship between class attendance and exam grades? Which sampling method is most appropriate for studying this relationship? Explain your answer.