Normal Distribution Explained: Is 68% Always 68%?

All videos + transcripts: https://clearstistics.com A bag of crisps says 150 grams, yet the machine never fills two bags exactly alike. Weigh 200 bags, drop a dot above each weight, and a hill grows: the normal distribution. Then the factory buys a more precise machine, and its curve stands three times as tall. Does the middle band now hold more bags? Make your guess before the answer. In this video: why "normal" is only the name of a shape, not a verdict on your data. Why the curve is a model that real data only comes close to. The two numbers that fix the whole curve, the mean μ (mu) and the standard deviation σ (sigma). Why you read "how many" from the area under the curve, never from its height. The 68-95-99.7 rule, and when you may use it. And why the tails get thinner and thinner but never touch zero. No prior maths needed. This is lesson 8 of the free course "Statistics, the basics": https://clearstistics.com/course The bag weights are a made-up model. Chapters: 0:00 One machine, 200 bags 0:21 "Normal" names a shape 0:58 Dots, then a curve 1:39 Two numbers: mean μ (mu) and sigma σ 2:07 A more precise machine: your guess 2:37 Taller, same share 3:18 The 68-95-99.7 rule 4:06 The tails: thin, never zero 4:37 One look back 4:57 In one picture 5:25 Next time Watch the series in order:    • Statistics for Beginners: Descriptive Stat...   More from the channel: @clearstistics Music: "Wholesome" by Kevin MacLeod (incompetech.com), licensed under Creative Commons: By Attribution 4.0 https://creativecommons.org/licenses/...