Your dataset

Drag a dot to change its value

Mean (average) 50.0 · 7 points · values 42–58

0255075100

Point A value

Focus a dot and use arrow keys. Shift moves by 10; Home / End moves to 0 / 100.

Distances from the mean

Subtract the mean, then square each deviation. Longer bars show larger distances.

Each point’s value, signed distance from the mean, and squared contribution to variance.
Point	Value	Deviation	Squared
A	42	-8.0	64.0
B	46	-4.0	16.0
C	48	-2.0	4.0
D	50	0.0	0.0
E	52	+2.0	4.0
F	54	+4.0	16.0
G	58	+8.0	64.0
Sum of squared deviations			168.0

Deviation = value − mean. Negative means left of the mean; positive means right. The bars share a −100 to +100 scale with zero in the center.

Average squared distance.

24.0

168.0 ÷ 7 = 24.0

Measured in squared units.

Spread in the original units.

4.9

√24.0 ≈ 4.9

A typical distance based on squared distances.

These 7 values are the whole population here, so divide by 7. This lesson describes the dataset; it does not estimate spread from a sample.

Standard deviation · preset means are 50; your edits may move the mean.

Mean 50.0; variance 24.0 squared units; standard deviation 4.9 original units.