### Standard deviation is a number that describes how spread out the values are.

A low standard deviation means that most of the numbers are close to the mean (average) value.

A high standard deviation means that the values are spread out over a wider range.

#### Example: This time we have registered the speed of 7 cars:

import numpy

speed = [86,87,88,86,87,85,86]

x = numpy.std(speed)

print(x)

0.9035079029052513 import numpy speed = [32,111,138,28,59,77,97] x = numpy.std(speed) print(x) 37.84501153334721 # Find the Variance import numpy speed = [32,111,138,28,59,77,97] x = numpy.var(speed) print(x) 1432.2448979591834 import numpy speed = [86,87,88,86,87,85,86] x = numpy.var(speed) print(x) 0.8163265306122449 Symbols Standard Deviation is often represented by the symbol Sigma: σ Variance is often represented by the symbol Sigma Square: σ2