 Hi, this is Dr. Don. I want to show you how to do permutations and combinations using stat crunch. I see a lot of students struggle with these questions on quizzes and make the mistake. The key thing you need to be remembering is that if order does not matter, if ABC and CBA are the same or equal, then you use a combination. And a combination is indicated by the NCR where N is the number of objects that we have in the pool and R is the number we're selecting. If order does matter, ABC and CBA are different, then you must use permutation in PR. So let's take a look at an example. There are 62 members of a club. Club members want to elect a president, vice president, treasurer and secretary. How many slates of officers are possible? Well here, logically, they select a president, then that person is taken out of the pool. So the order does matter. They select the president first, then the vice president, then the treasurer and secretary. So we need to use permutations to do this. I have stat crunch open. To do a combination or permutation problem, we need to use the data, compute, expression tool. And we're going to click on bill. We'll do the permutation part. So I'm going to scroll down here until I find something that looks like permutation. And there it is, P-E-R. And it enters the basic function. We need to enter our N, which is 62. And our R, I'm going to move this over, is 4. Click OK and compute. And we get that the number of slates of officers is large. It's 13.388 million different ways that we can select those officers as order matters. The second part, from the 58 members who were not elected officers, the club members want to appoint a planning committee of four who will then select their chairperson. How many ways can the committee be selected? Well, it doesn't really matter which person we select first because they're going to elect their chairperson later. So any person can be the first person chosen for the committee. That tells me that order does not matter, which means we use combination. Back in StatCrunch, I'm going to go back to data, compute, expression, build. And this time I want to find something that looks like combination and there it is, COM. And we need to enter our N this time. It's 58 because we had four people elected officers, but we're still electing four. So I'm going to click OK, compute. And you can see that we have only, it's still a lot, 424,270 ways that we can select four people out of those 58 members. So remember that difference. If order does not matter, you use the combination NCR. If order matters, then you use the permutation NPR. Hope this helps.