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Step 4 Divide the sum of squares by sample size -1 (n-1).

24 ÷ N – 1 = 24 ÷ 5
VARIANCE = 4.8

This value is the variance.
Standard Deviation

Standard deviation is a statistic that measures the degree of dispersion of a data set relative to its average. When
determining the deviation of each data point from the average, the standard deviation is calculated as the square root
of the variance. If the data points are farther from the mean, the greater the deviation in the data set; therefore, the
more spread out the data, the larger the standard deviation.

∑ (xx 2
− )
σ=
n
Where,
= Standard deviation
x = Each value in the data set

x = Mean of the data
n = Total number of values
Relation between Standard Deviation and Variance:
Standard deviation is the square root of variance.

σ= Variance
Variance tells how spread out the data is, and standard deviation shows this spread in the same units as the data.
Using the previous example, we have to calculate the square root of the variance in order to find the standard deviation.

VARIANCE = 4.8
STANDARD DEVIATION = 4.8 = 2.19

140 Touchpad Artificial Intelligence - XI