Question

If the mean of the following distribution is 2.6, then the value of y is:

Variable (x)	1	2	3	4	5
Frequency	4	5	y	1	2

विकल्प

• 3

• 8

• 13

• 24

Answer 1

8

Explanation:

Consider the following table:

Variable (x)	Frequency (f)	fx
1	4	4
2	5	10
3	y	3y
4	1	4
5	2	10
	∑f = 12 + y	∑fx = 28 + 3y

Now, 

Mean = `(sum"fx")/(sum"f")`

`2.6/1 = (28 + 3y)/(12+y)`

31.2  + 2.6y = 28 + 3y

3y – 2.6y = 31.2 – 28

0.4y = 3.2

y = `(3.2)/(0.4)`

y = 8