Marks 1 2 3 4 5
Frequency 2y - 2 y - 1 3y - 4 3 - y 6 - 2y

The table above is the distribution of data with mean equals to 3. Find the value of y.

A.

5

B.

2

C.

3

D.

6

Correct answer is B

Marks (x) 1 2 3 4 5  
Frequency (f) 2y - 2 y - 1 3y - 4 3 - y 6 - 2y 3y + 2
fx 2y - 2 2y - 2 9y - 12 12 - 4y 30 - 10y 26 - y

Mean = \(\frac{\sum fx}{\sum f}\)

\(3 = \frac{26 - y}{3y + 2}\)

\(3(3y + 2) = 26 - y\)

\(9y + 6 = 26 - y\)

\(9y + y = 26 - 6\)

\(10y = 20 \implies y = 2\)