The police in a certain city are investigating whether the proportion of minor traffic accidents is greater on Friday nights than on Sunday nights. As part of the investigation, they select a random sample of police calls from Friday nights and a random sample of police calls from Sunday nights. From both samples, they record the sample proportion of calls that involved minor traffic
accidents. Let Pp represent the proportion of all Friday night calls, and let Ps represent the proportion of all Sunday night calls. Which of the following are the correct hypotheses for the
investigation