| 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.
- 5
-
2
- 3
- 6
The correct answer is: B
Explanation
| 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 = \(\frac{\sum fx}{\sum f}\)
\(3 = \frac{26 - y}{3y + 2}\)
\(3(3y + 2) = 26 - y\)
\(9y + 6 = 26 - y\)
\(9y + y = 26 - 6\)
\(10y = 20 \implies y = 2\)
There is an explanation video available .