Question

0.26. Find out Mean deviation by Step Deviation Method from the
following data-
Size 140–150 150-160 160-170 170-180 180-190 190-200
Frequency 4 6.
10
18
9
3​

Answer 1

Step-by-step explanation:

Step deviation method:

Size 140–150 150-160 160-170 170-180 180-190 190-200

Frequency : 4, 6, 10, 18, 9, 3. :Sum of fi=50

Xi: 145, 155, 165, 175, 185, 195.

a=165.

di=xi-a: -20, -10, 0, 10, 20, 30.

h=150-140=10.

ui=di/h:. -2, -1, 0, 1, 2, 3.

fi×ui: -4, -6, 0, 18, 18, 9.

Sum of fi×ui=-10+45=35.

Mean:

$= a + ( \frac{fiui}{fi} ) \times h$

=>165+(50/35)×10

=>165+100/7

=>165+14.2

Mean=>179.2.