Question

What is the standard deviation of the data set given below? 2,6,7,10,10

Answer 1

Average = (2 + 6 + 7 + 10 + 10)/5 = 35/5 = 7

x - mean,  square.

2 - 7 = -5,  -5² = 25

6 - 7 = -1,  -1² = 1

7 - 7 = 0,  0² = 0

10 - 7 = 3,  3² = 9

10 - 7 = 3,  3² = 9

Sum of square = 25 + 1 + 0 + 9 + 9 = 44
 
Variance = 44/5 = 8.8

Standard deviation = √variance = √8.8 ≈ 2.966