I don’t understand why you used VARPA to calculate the sample variance (2:35 in the video). I read that this formula is for a population and not for a sample (VARA is for a sample). And we have a sample right? We even use the T Statistic in the case.
Furthermore so far in the course we have always used VAR.P or VAR.S to calculate variances. Why changing now? I get the difference between VARPA and VAR.P (or VARA and VAR.S) is how text is treated (ignored or counted with a value of 0) but there is not text in our example.
Finally, you used an array formula (Excel adds brackets when you enter the function with Ctrl+Shift+Enter), why does VARPA in combination with IF function only works with an array formula? I tried VARPA and VAR.S without the brackets and it returns an error.
Thank you for your answers,
Note: in the excel course your don’t cover array formula so it took me time to understand why my formula was not working.