This video describes the concept of Inferential Statistics - in particular hypothesis testing for a single population mean. This is the area of Statistics where we use a sample (some subset of the whole group we wish to describe) in order to infer (deduce) something about the whole group (known as the population).
For example, we may want to know the population mean response time to a medication, i.e., how long on average before a painkiller takes effect. It’s not possible to test the medication on an entire population of individuals requiring such assistance (time, costs, logistics prevent this). Instead we must assess a sample of individuals from that population. We use the results from the sample to make an inference about the entire population.
By taking a sample we introduce a source of uncertainty, as there are many possible samples that could be obtained. Hence we need to account for this uncertainty when making decisions about the population. It is recommended that you are familiar with the content of the Introduction to Statistics and Random Variables videos before viewing this video.