One of the most basic things we do all the time in Data Analysis (i.e. Statistics, Machine Learning or any other sort of number crunching type thing) is calculate the mean, variance and standard deviation. This StatQuest walks you through these tasks and help you avoid a very common pitfall that is all too easy to fall into. NOTE: This StatQuest assumes are already familiar with... ...Histograms: https://www.youtube.com/watch?v=qBigTkBLU6g ...Statistical Distributions: https://www.youtube.com/watch?v=oI3hZJqXJuc ...the Normal Distribution: https://www.youtube.com/watch?v=rzFX5NWojp0 ...and Population Parameters: https://www.youtube.com/watch?v=vikkiwjQqfU NOTE: For more details on why dividing by 'n' underestimates the population variance and why we square each term, check out the follow up StatQuest: https://www.youtube.com/watch?v=sHRBg6BhKjI For a complete index of all the StatQuest videos, check out: https://statquest.org/video-index/ If you'd like to support StatQuest, please consider... Buying The StatQuest Illustrated Guide to Machine Learning!!! PDF - https://statquest.gumroad.com/l/wvtmc Paperback - https://www.amazon.com/dp/B09ZCKR4H6 Kindle eBook - https://www.amazon.com/dp/B09ZG79HXC Patreon: https://www.patreon.com/statquest ...or... YouTube Membership: null ...a cool StatQuest t-shirt or sweatshirt: null ...buying one or two of my songs (or go large and get a whole album!) https://joshuastarmer.bandcamp.com/ ...or just donating to StatQuest! https://www.paypal.me/statquest Lastly, if you want to keep up with me as I research and create new StatQuests, follow me on twitter: https://twitter.com/joshuastarmer #statquest #statistics