Question

individual series :-

x:- 5,10,8,9,12,18,13,6,3,9,4,5 find.


Arthimatic mean..

plz solve this answer it's urgent.....​

Answer 1

Answer:

Short-cut Method.

ANSWER:

Families

Monthly income

(X)

Deviation from the Assumed average

(d = X − A) (A = 75)

1

2

3

4

5

6

7

8 70

10

500

75 (A)

13

250

8

42 −5

−65

425

0

−62

175

−67

−33

(N) = 8

(ΣX)=968 Σd = −232 + 600 = 368

where,

N= Number of items

ΣX= Total of monthly income of all the families

Σd= net sum of deviations

Calculation of Mean by Direct Method

X=

ΣX

N

=

968

8

=121

Calculation of mean by short cut method

X=A+

Σd

N

or, X=75+

368

8

or, X=75+46⇒X=121

So, mean monthly income of a family is Rs 121.