Видео

I know this was so confusing to me when I was first learning it, but in the video, Y bar refers to the data set of means from many different samples taken from the population. So, suppose the population (Population means literally everyone) is 50 people, and you bring a sample (Not everyone) of 3 people to conduct your research, then you decide one sample of 3 people is not enough, so you decide to randomly select 3 people again, and you do this let's say 5 times in total. Now, each sample (of 3 people) has their own average. But remember you did this 5 times! So, with those 5 samples, where each sample has it's own mean, you create a new data set representing the means of all the samples you collected. I like to call it SampleCeption. So, to conclude, Y bar is like the set of 5 sample means that you collected and calculated, so when she writes Y1, she is now talking about the sample of 3 people that you did your research with. Those 3 people have their own mini cute variance, as opposed to the variance of Y bar which describes the variance of the MEANS of all 5 samples. I really hope this cleared up any confusion for you, or anyone reading this. Don't mind me being a year late haha