Statistics
Mean Deviation and Variance from Frequency Table
nta_pyq_2023_apr
Grade 11
Question:
For the data $x: 1,3,5,7,9$; frequency $4,24,28,\alpha,8$ with mean 5, then $\dfrac{3\alpha}{m+\sigma^2}$ is equal to _______.
Step-by-Step Solution
Key Concept: Mean $=5\Rightarrow\alpha=16$. Compute $m$ (mean deviation) $=\frac{8}{5}$ and $\sigma^2=\frac{22}{5}$.
$\alpha=16$. $\frac{3\times16}{8/5+22/5}=8$.
Correct Answer: 8