 This is a video on how to find probabilities using the normal distribution. Assume that the readings at freezing on a batch of thermometers are normally distributed with a mean of 0 degrees Celsius and a standard deviation of 1 degrees Celsius. A single thermometer is randomly selected and tested. Find the probability of obtaining a reading greater than negative 3.086 degrees Celsius. The best thing to do for these types of questions is to first start off with the bell curve. You really want to draw a picture for each of these options here. Now I know from the question that the mean of my distribution is 0 and my standard deviation is 1. This will always be the case for a standard normal distribution. A normal distribution that is standardized standard normal distribution. So in the middle I have my mean of 0 and then my goal is to find out the probability, in other words the area under the curve, the area under the curve represents probability that a data value is greater than negative 3.086. So does negative 3.086 lie to the left of 0 or to the right of 0? It certainly does lie somewhere over to the left. So I'm going to mark that negative 3.086. So that's my cutoff line. I want to know the probability that a reading is greater than this number. So I need to find the area under the curve to the right of this number. So this entire shaded region. How do we do that? We're going to use our technology Google Sheets. So go to Google Sheets, you'll go to the compute tab, then you'll go to the normal area. Our mean in this case would be 0. Our standard deviation sigma would be 1. Our lower bound is negative 3.086 and our upper bound is actually infinity, but we can't actually type that in. Instead I use 6.9 which is a really really big number. You could use more 9s if you want, but it's really not going to change your result very much. So your probability will show up here in cell E6. It's 0.9989 which rounds to 0.999 if I round the four decimal places. So 0.999 is going to be our answer, 0.999. And if you want to show the zero at the end just to show that you did round the four decimal places, that's perfectly fine. That's all we have for you currently. So thanks for watching.