Question

using direct method find the standard deviations from the following data ( size 0-2,2-4,4-6,6-8,8-10,10-12)/(frequency 2,4,6,4,2,6)​

Answer 1

Answer:

x

i

f

i

f

i

x

i

∣x

i

−Mean∣ f

i

∣x

i

−Mean∣

4 2 8 6.2 12.4

6 1 6 4.2 4.2

8 3 24 2.2 6.6

10 6 60 0.2 1.2

12 4 48 1.8 7.2

14 3 42 3.8 11.4

16 1 16 5.8 5.8

n=20 ∑f

i

x

i

=204 ∑f

i

∣x

i

−Mean∣=48.8

Mean =

n

∑f

i

x

i

=

20

204

=10.2

Mean deviation about Mean =

n

∑f

i

∣x

i

−Mean∣

=

20

48.8

=2.44