Kai, a seventh grader, wants to determine the average number of times the families in his neighborhood visit the pool during the summer. he samples the families of four of his classmates. which improvements could kai make to his sample to increase the validity of the results? check all that apply. sample more families/ sample families that have children who are not in seventh grade/ sample families that do not have children /sample families whose answer to the survey question is predetermined/ sample families living in every third house in the neighborhood