Calculate standard deviation from the following data:

x: 2 4 6 8 10

f: 4 6 8 7 5

x : 2,4,6,8,10

f : 4,6,8,7,5

mean=6.2

x f fx x=X-mean ^{x2 fx2}

2 4 8 -4.2 17.64 70.56

4 6 24 -2.2 4.84 29.04

6 8 48 - 0.2 0.04 0.32

8 7 56 1.8 3.24 22.68

10 5 50 3.8 14.44 72.2

total= 30 186 194.8

mean= total of fx/ total of f

= 186/30

= 6.2

standard deviation= square root of total of fx / total of f

= square root of 194.8 / 30

= square root of 6.50

= 2.550

ans: standard deviation is 2.550