A regional store manager wants to test whether increasing store hours increases profits, so they randomly select half of their locations to stay open an extra hour later in the evenings and compare profits between stores at the end of the month. They notice that stores open later saw higher profits on average. Is this an experiment or an observational study? Can they determine the extra hours caused the increase in sales?

Welcome back. For this problem, we have a regional store manager who wants to test whether increasing store hours increases profits. So they randomly select half of their locations to stay open an extra hour later in the evenings and compare profits between stores at the end of the month. They noticed that stores open later saw higher profits on average. We wanna know, is this an experiment or an observational study, and can they determine the extra hours caused the increase in sales? As a reminder, an experiment is all about comparing whether or not a change affects a situation by looking at what happens when we make the change and what happens when we don't. An observational study is all about collecting data at the current state of things. In this case, we did enact a change. Some stores stayed open an hour later. Then we compared the results or profits of both the stores that had the regular hours and the stores that had the extended hours, so this would be an example of an experiment. In experiments, we can assume causation. So, yes, we can determine that the extra hours caused the increase in sales. Great work.