A store is interested in whether they should adjust their store hours, so they choose a random day to poll all people entering the shop and ask them if they would prefer the store to change their hours. Is this a simple random sample? Can we assume this is a representative sample?

Welcome back. For this problem, we have a store interested in whether they should adjust their store hours. So they choose a random day to pull all people entering the shop and ask them if they would prefer the store to change their hours. We wanna know if this is a simple random sample and also if we can assume this is a representative sample. For a simple random sample, we need all possible members of our population to be in a large pool and we randomly pick some out to be subjects in our sample. But here, we're not picking our subjects randomly. We're picking the day to do the poll randomly and then just talking to every person that happens to come into the shop on that day. So that's not a simple random sample. So we can say no to that first question. What about the second question? Can we assume that this is a representative sample? Well, let's think about it. Do we think that the people that shop on any one given day could represent the entire customer base of a store? I would say probably not no. Let's say, for example, the day is a Tuesday. Well, we could logically see how people that work a regular nine to five job might have a difficult time shopping at the store on a Tuesday and might prefer to shop on a weekend day, say Saturday. But we could also see if they picked a Saturday, that people that might not have your typical nine to five might prefer to shop on a different day, say, maybe on a Tuesday. So we can see how just picking one day, you might get a different customer base. And so we might not get a fully representative sample by just talking to customers that shop on one particular day. So again, we can say, no, this is not necessarily a representative sample. At least, we don't have enough information to assume that it is. Great work.