"In a study of 87 French and Swiss college students, researchers gave half of them sunscreen with a protection factor of 10 and the other half with a factor of 30. The students, who weren't told which lotion they received, went on summer vacations and recorded the amount of time they spent in the sun. Users of the stronger sunscreen spent 25% more time in the sun, mostly sunbathing, the study found . . . students in the study often waited until their skin turned red before rushing to the shade."5
a. Is time spent in the sun being treated as a quantitative or a categorical variable?
b. How would researchers summarize time spent in the sun for each group (those with the stronger and those with the weaker sunscreen)?