Before meeting with her reading group, Holly collected information about the history of a book that had been recommended to the group. During the group's next meeting, Holly shared her findings as the group discussed whether to add the book to its reading list. What kind of leadership need did Holly's actions fulfill?

Donald is studying the eating habits of all students attending his school. he samples the population by dividing the students into groups by grade level and randomly selecting a proportionate number of students from each group. he then collects data from the sample. which type of sampling is used? select the correct answer below: systematic sampling convenience sampling stratified sampling cluster sampling