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
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
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 = \(\frac{\sum fx}{\sum f}\)
\(3 = \frac{26 - y}{3y + 2}\)
\(3(3y + 2) = 26 - y\)
\(9y + 6 = 26 - y\)
\(9y + y = 26 - 6\)
\(10y = 20 \implies y = 2\)
Source: Myschool Past Questions Archive (Record #55439)