The Standard Deviation and Variance Explained in One Minute From Concept to Definition Formulas

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The Standard Deviation and Variance Explained in One Minute From Concept to Definition Formulas

One Minute Economics · ⏱ 1:47 · 547.1K مشاهدة · 8 years ago

📺 شاهد كل صفحات قناة "One Minute Economics"

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practically nobody calculates the standard deviation by hand as there are tons of applications that do it for you however it's crucial to understand what exactly this term means and you know why we care about it to understand what the standard deviation tells us think about the huge room in which one on the left side there are all of the male members of your family father grandfathers cousins and so on two on the right side there are all of the female members of your family for each side will only measure one thing the average length of their hair if you have let's say standard western family quick unscientific look will probably reveal that most men have short hair whereas when it comes to the women there's lot of variation from very short to very long hair statistics Enthusiast will quickly tell you that the male group has low standard deviation in other words that more of the guys have hair lengths close to the average than with the female group next we'll get scientific by one calculating the average hair size for the male as well as female group in other words the mean to sub subtracting the mean from each individual value then multiplying the result by itself in other words squaring it three we once again calculate the mean but this time the mean for the previously calculated Square differences and that mean is called the variance please note that we divide the sum by the total number of values if the people in question represent the entire group or if only sample is picked randomly we divide by the number of values minus one four we calculate the square root of that variance and there we have it that's the standard deviation the bottom line is this whether you choose to calculate the standard deviation or not the most important thing is realizing that its role is helping you better understand the nature of your data by knowing how close to the average individual values tend to be