Hospitalization rates for eating disorders are highest among women aged

We wish to test the hypothesis that music improves learning. We compare test scores of students who study to music with those who study in silence. Which of the following is an extraneous variable in this experiment?

a. the presence or absence of music b. the students' test scores c. the amount of time allowed for studying d. silence

Howard Gardner is to ___ type(s) of intelligence, as Charles Spearman is to ____ type(s) of intelligence

a. one; nine b. nine; one c. three; seven d. seven; three