 Hello, this is a video about two sample hypothesis testing using the matched pairs method for the mean difference between two groups of data. You wish to test the following claim, the alternative hypothesis H1, at a significant level of alpha equals 0.001. For the context of this problem, the mean difference is equal to the mean of group 2 minus the mean of group 1, where the first data set represents pre-test and the second data set represents a post-test. Now, some legal requirements to use the matched pairs method. You believe the population of difference in scores is normally distributed, but you do not know the standard deviation. We need to find the test statistic, the p-value. We'll compare it to alpha, then we'll come to a conclusion based on our hypothesis. So we actually do have to put raw data into our Google Sheets document. The easiest way to do this is to go to the question itself, and you could try copying and pasting the data directly into Google Sheets, but sometimes this is tricky. So I found the easiest to take that data, copy it, pasting it into Excel, or some sort of spreadsheet software, and then copying the data over column by column in the Google Sheets. This has always worked for me. So Google Sheets will go to two variable stats. It may take a little while to get to this tab and for calculations to be done, but I'm going to paste my first group of data, my pre-test, and then just copy over the second group of data, my post-test, paste it in cell B2, and it will fill the cells following it, and your answers that you want for this question are going to be in column O. So you need to mosey on over to column O, and if you'll notice there's all these errors currently, it's because it does take a little bit of time to calculate. So it gives us software some time to calculate, it's still calculating, just be a little bit patient with it, it's working as hard as it can. So it looks like our test statistic will be negative 2.14, and we're dealing with a left tail test because we're dealing with less than, so p-value is about 0.0326, those are the two numbers that we need here. And although it does take a little while to get these calculations, it's probably better that Google Sheets is doing it than you, it might take a little while. So our test statistic is negative 2.14, and our p-value is 0.0326, let's compare the p-value to alpha. Remember, our claim is the alternative hypothesis, we have our p-value, we have our alpha given to us in the question, the p-value is definitely greater than alpha, which means we fail to reject the null hypothesis. So we fail to reject the null hypothesis, our original claim does not include equality. So we have the general format of our conclusion here, which happens to be there is not sufficient evidence to support the claim that the mean difference of post-test from pre-test is less than zero. So that's an example of using the match pairs method, thanks for watching.