Contacting Parents A research organization conducts a survey by randomly selecting adults and asking them how frequently they contact their parents by phone. The results are shown in the figure. (Adapted from Pew Research Center)

(a) Use a sign test to test the null hypothesis that the proportion of adults who contact their parents by phone weekly is equal to the proportion of adults who contact their parents by phone daily. Assign a sign to adults who contact their parents by phone weekly, assign a sign to adults who contact their parents by phone daily, and assign a 0 to adults who answer “other.” Use

(b) What can you conclude? In Exercises 25 and 26, use StatCrunch to help you test the claim about the population median.