 This is a video on one sample hypothesis testing, finding the critical value. Now, you are performing a right-tailed Z test. So we're dealing with the standard normal distribution. If alpha equals 0.025, that would be my level of significance here, find the critical value. One thing I want to make clear here is in hypothesis testing, any time you want to find the p-value, it uses the test statistic. p-value is an area under the curve whereas the test statistic is an x-axis data value. Now, any time you want to find a critical value, it is actually associated with alpha or your level of significance. Alpha is area under the curve whereas the critical value is the x-axis value. So in this case, I'm finding a critical value, so I'm going to have to need to use alpha here. So first thing you do is look at what type of test you have. You have a right-tailed test, which means you'll have a tail over here in the right side of your bell curve. And your critical value is going to be the value separating the tail from the rest of the graph. So it's a right-tailed test. Once again, that's why my tail is over here on the right-hand side. Alpha is the area of the tail. Alpha is the area of the tail. In this case, that would be 0.025. Alpha is the area of this tail. So what I have to do now is I actually need to find this critical value z. Well, to find x-axis values, I need to know the area to the left. So area to the left equals what? Well, if the area to the right is 0.025, area to the left is 1 minus 0.025, which is 0.975. We need this for Google Sheets. We always need the area to the left to only find data values. So 0.975. And Google Sheets, you know that your mean is going to be zero. Standard deviation is one because you're dealing with z, the standard normal distribution. And you know, area to the left is equal to 0.975. So let's go to Google Sheets and let's find this critical value. And Google Sheets, make sure you're in the compute tab and you're gonna go to the normal area. Zero is mu, sigma is one. And since I'm looking for data value, I need left-held area, which is 0.975. And lookie here, to two decimal places, we get a critical value of 1.96. Our critical value in this case is 1.96. So critical value is 1.96. And that is the answer. Thanks for watching.