Statistics: What does one standard deviation, 2 SDs, 3 SDs, etc, mean? And how do I turn SD to a percent?

What does one standard deviation, 2 SDs, 3 SDs, etc, mean? And how do I turn SD to a percent?





I've learned the concept of standard deviation, but when I learned it there was nothing about there being multiple standard deviations. When I do the calculations based on data values, I got one number for the standard deviation and it just indicates how far the data values are from their mean on ';average'; basically. So how can there be multiple values for this? It's a single value answer. I believe that saying X is 2 SDs from the mean means something different than SD used in the context I described in the beginning.





Furthermore, I have to convert the SDs of 2 samples into percents and then compare them. How do I do it? And also I need help visualizing the answer I get after converting SD to percent. How does a 5% SD compare to a 25% SD if I were to visually represent it somehow.Statistics: What does one standard deviation, 2 SDs, 3 SDs, etc, mean? And how do I turn SD to a percent?
no in your example if the SD were 10 then X would be 20 from the mean.


to get percentage 100SD/ mean


if you visualise the distribution as a bell curve, one with a SD of 25% will be wider and flatter than one with 5%.