To survey the student body, Bill separates students according to their year in school and then randomly selects students to interview from each group. Which sampling plan is Bill utilizing?

_____ recognized the role of consciousness when he proposed that people have cognitive needs to know and to understand

a. Maslow c. Seligman b. Zuckerman d. Rotter

Which best describes the early menstrual cycles of a typical teenage female?

a. Regular and with ovulation b. Regular and without ovulation c. Irregular and with ovulation d. Irregular and without ovulation