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Data Analysis Data Analysis Basics Getting to Know Your Data Is Our Data Normal?

Bernardo Augusto García Loaiza
Bernardo Augusto García Loaiza
Courses Plus Student 792 Points

What is the reason to get or reference three standard deviations?

Why in the normal distribution, we work with three standard deviations? Are they only three?

This is due to the property related to how many values occurr within one standard deviation in relation to mean? (this is referenced in the video ... )

Why take as a reference three standard deviations to address?

Is this one constant concept into normal distributions?

3 Answers

We stop after 3 standard deviations because 99.7% of normally distributed data (i.e. data that fits a normal distribution) is within 3 standard deviations from the mean. This is a property of ALL normal distributions, which is one of the reasons why they're so useful. More on that can be found here:


Countif function in google sheets in showing an error message, "expecting 2 arguments but received 4 arguments". Any suggestions on how to get through this error.

You should post as a new question. But I'm guessing you're using COUNTIF, when you should be using COUNTIFS.

Will post as a new question next time and thanks got it