Question

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

Variate x	1	2	3	4	5
Frequency f of x	4	5	y	1	2

• A. 24
• B. 13
• C. 8
• D. 3

Answer 1

Answer: (C)

8

Answer 2

We know that, Mean$= \frac{\sum_{i = 1}^{n}{f_{i}x_{i}}}{\sum_{i = 1}^{n}f_{i}}$

i.e., $2.6 = \frac{1 \times 4 + 2 \times 5 + 3 \times y + 4 \times 1 + 5 \times 2}{4 + 5 + y + 1 + 2}$

or $31.2 + 2.6y = 28 + 3y$ or $0.4y = 3.2$ ⇒ $y = 8$.