Query in lecture video: Unknown Standard Deviation

Hey guys,
I have a small query in the aforementioned lecture video. For calculating the margin of error with unknown standard deviation for the population, we use the standard deviation for the sample. My query is how do we calculate the standard deviation for the sample here? Do we use the unbiased estimate and divide by n-1, or do we use the biased estimate and divide by n here?


Hi @Elemento!

Sorry for the late response.

As I can see here, the value used is s, which is the sample standard deviation, which it is defined by the square root of the sample variance which has n-1 in the denominator. This will make the transformed variable follow a t-student distribution.

Could you elaborate on why you think you got confused here? So we can improve videos to avoid such confusions.