Course Lessons
chapter 4 : Data Variation
2. Standard Deviation (SD)
Standard deviation is the square root of the variance. It
measures how far, on average, each value lies from the mean. Since it uses the
same units as the data (unlike variance, which is in squared units), itβs
easier to interpret.
Formula (Population):
Ο=Ο2\sigma = \sqrt{\sigma^2}Ο=Ο2β
Example:
Using the previous variance = 2
Standard deviation = β2 β 1.41
That means, on average, the values are about 1.41 units away
from the mean.