25 Jan 2021

Posted on:

08 Dec 2020

0

# How did you get this P-Value

P-Value is calculated by: 1- the number from the table when it is a one sided test The number from the table was a t-table because we did not know the population variance of a single population. The number that was taken from the T-table was 1.833 (which is stated in the photo above) And even if I decided to use the z-table to find the number the number that comes up is .9664 when I use the z-table to find 1.833. You obviously don't divide by 2 because it's one sided. Please explain how you got this P-Value. If you are going to change the calculation of something, or you are going to change a calculation that you explained already you need to explain this. This has been very frustrating taking these courses because this is not the first time this has happened. And I have to say that I am very disappointed that I am having a hard time following your program considering your teaching methods. Especially since this is online and you can't just ask a question. I have spent many hours watching your videos and I have to say that I am very disappointed with the Probability and Statistics course. There are many situations where the calculations have changed from one video to the next. That is poor teaching.
1 answers ( 0 marked as helpful)
Posted on:

25 Jan 2021

1

Hi,
I was asking myself the same thing. I stumbled upon a similar question to this one where they answered that they've used the socstatistics online P-Value calculator.

However, it was at a later lecture that I found out how to manually get the P-Value when using the T-Statistic. In order to get the P-Value, you would need to find the alpha that corresponds to the given T-Score on the table. In the case you're asking about, because the T-Score is 0.53 and the T-table provided does not have critical values lower than 1.282, we would have to use an online P-Value calculator or extrapolate.

Take the case of this lecture: https://learn.365datascience.com/courses/statistics/test-for-the-mean-dependent-samples

Here the degrees of freedom are 9 and the T-Score is 2.29. This is a value that, while not exactly on the table, it is between the values corresponding to alphas (levels of significance) of 0.025 and 0.01. Therefore, the P-Value must be a number between these two. We could use interpolation to get an approximation of this number or once again use an online P-Value calculator. I used both methods and ended up with the same result.

Hope this clarifies two things:

1. How they got the P-Value you're asking about
2. That the manual way of finding the P-Values differs when using a Z-Score/Table and a T-Score/Table