 This is a video on how to use probabilities from the normal distribution to find data values. The distribution of values is normal with a mean of 148.2 and a standard deviation of 73.7. Find the 51st percentile, which is the score separating the bottom 51% from the top 49%. So what they give me here is, first, normally distributed data with a mean of 148.2 and a standard deviation of 73.7. So I'll go ahead and label my bell curve here, label my mean of 148.2. I want the data value separating the bottom 51% from the top 49. So I need to find the data value, which will separate. So I'll draw my little separation bar here. 51% of the data from 49% of the data or .51 from .49. So my data value that I'm trying to find and call it X is the data value whose area to the left is .51. So since I know probabilities or since I know areas, I can use this information to calculate my data value. So what I have to do is I have to go to my Google Sheets document, go to the compute tab and go to the normal tab. In this case, the mean is 148.2 and the standard deviation is 73.7. If I was to calculate a probability, I would need to put in a lower and upper bound, but I'm not. I want to find a data value now. I already know my probability. So what you do is the data value you want to find, you find the area under the curve to the left of it, the left tail area. So the area to the left of the data value I want to find is .51. Which means our percentile, our answer to the question is 150. 150 is our answer. That is to score separating the bottom 51% from the top 49%.