 This is the third video on estimating or figuring out the uncertainty of the length of a cat. We already did it by estimation and by using the min-max method. Now, the other two methods that you can use from statistics is average and standard deviation. You could either use the formulas or if you like me a bit on the lazy side, you're gonna use Excel to do that for you. Okay, so first what I did, I copied my 17 measurements in here. Now the first thing I'm going to be doing is calculating the average. Now my Excel is set to English, so the formula will be equals average. If you have it in French, for example, it will say equal Moyen. So you have to go with whatever the language is. So as you see, I simply think average and then I mark all values. So from C4 to C20, I want Excel to calculate me the average. Hit enter, that's done. Now average deviation, similar, formula is AVEDEV. Open bracket. Then again, I'm gonna mark all of those and hit enter. This is my average deviation and standard deviation, STDEV. Open bracket, close, mark the whole thing, enter, and that's it. So I have my three values from Excel. Now let's go back to the board. So we're back from Excel. I copied over the average Excel gave me. I copied over the average deviation and the standard deviation. Now what do we have to do? Well, for the average deviation method, we simply copy the value over and as before, I prefer to do only 16 figs, so 0.01, average deviation plus 0.01 meter. And as the main value, I take the average itself with the same number of significant figures. So in this case, 0.6. And for standard deviation to the same thing, I round it to 1.6 figs, so plus minus 0.1, and the average itself to 1.6 fig. So I have another value. So what do we get if we compare all methods here? When I did the estimation, that was definitely the fastest because I only had to do one measurement, and I got a very high uncertainty because I was very conservative. I didn't think I have high precision in my measurements. When I did the minmax method, the average deviation, the standard deviation, in this case, it turned out that value here became the same for all of them. It could have been different here because here I used max plus min over 2 and not the average. So here that's the coincidence that this is exactly the same number. Here it has to be the same number. Then for the uncertainty itself, the minmax method is the one that takes in every single measurement. Every measurement is in, so I have the highest uncertainty. However, if I look at average and standard deviation, I get much lower uncertainties here with 1.6 fig, the same value, but it looked like standard deviation would have given me a bit of a higher value. Why? Because we square the difference from the average, so outlayers have a bit of a bigger impact, but in this case here didn't make any difference. So all of these should be accurate. The statistical methods here gave me a higher precision. However, if I don't have much time, estimating might just do the trick because the answer is accurate. It might not be very precise, but the answer is accurate. All of these values do agree with each other.