Question

1. Using step-deviation method, calculate standard deviation and coefficient of St. Dev of the following series Income 0-10 10-20 20-30 30-40 40-50 50-60 60-70 70-80 No of Labour 5 10 20 40 30 20 10 4​

Answer 1

Answer:

The formula used for arithmetic mean of grouped data by step deviation method is,

X

=A+

∑f

∑fu

×i

A= Assumed mean of the given data

∑ = Summation of the frequencies given in the grouped data

∑fu = Summation of the frequencies and deviation of a given mean data

u=

i

(x−A)

i= Class interval width

X

= arithmetic mean

X

=45+

70

63

×10

=45+9

=54

Answer 2

Answer:

The formula used for arithmetic mean of grouped data by step deviation method is,

X

=A+

∑f

∑fu

×i

A= Assumed mean of the given data

∑ = Summation of the frequencies given in the grouped data

∑fu = Summation of the frequencies and deviation of a given mean data

u=

i

(x−A)

i= Class interval width

X

= arithmetic mean

X

=45+

70

63

×10

=45+9

=54

Answer 3

Answer:

The formula used for arithmetic mean of grouped data by step deviation method is,

X

=A+

∑f

∑fu

×i

A= Assumed mean of the given data

∑ = Summation of the frequencies given in the grouped data

∑fu = Summation of the frequencies and deviation of a given mean data

u=

i

(x−A)

i= Class interval width

X

= arithmetic mean

X

=45+

70

63

×10

=45+9

=54