MODULE 6 – MEASURES OF VARIATION
MEASURES OF VARIATION
are different measures that describe how
spread or scattered a set of data is.
=
=
RANGE
=
Range is the difference between the
highest score and lowest score.
=
=
r = highest score – lowest score
=
VARIANCE (𝜎 2)
Variance is the average of the squared
differences from the mean.
=
∑(𝒙 − 𝒙)𝟐
𝝈𝟐 =
𝑵−𝟏
=
=
x = individual value/score
x̅ = the mean of the data
𝑁 = total number of scores
=
=
=
STANDARD DEVIATION (𝜎)
Standard Deviation is almost similar to
variance. It tells us on average how far
each score lies from the mean.
=
=
=
𝒙)𝟐
∑(𝒙 −
𝝈=√
𝑵−𝟏
=
=
=
=
𝑥 – individual value/score
𝑥 – the mean of the data
𝑁 – total no. of scores
EXAMPLES
=
=
=
=
=
=
1
=