Your set is 2, 5 and 8.
In order to calculate the standard deviation, first, you need to calculate the mean of the scores:
m = (2 + 5 + 8) / 3
= 15 / 3
= 5
Then, find the variance: subtract the mean from each value, square the results, sum them up and divide it by the number of scores.
(2 - 5)² = 9
(5 - 5)² = 0
(8 - 5)² = 9
Therefore:
v = (9 + 0 + 9) / 3
= 18 / 3
= 6
The standard deviation is the square root of the variance:
σ = √6
= 2.45
In conclusion, the standard deviation can be calculated by the formula:
[tex]\sigma = \sqrt{ \frac{\sum(v - m)^{2} }{n} } [/tex]
