Statistics
Variance from Frequency Table
nta_pyq_2024_jan
Grade 11
Question:
The variance $\sigma^2$ of the data \begin{array}{|c|c|c|c|c|c|c|c|}\hline x_i&0&1&5&6&10&12&17\\\hline f_i&3&2&3&2&6&3&3\\\hline\end{array} is
Step-by-Step Solution
Key Concept: $N=\sum f_i=22$. $\bar{x}=\sum f_ix_i/N=176/22=8$. $\sigma^2=\sum f_ix_i^2/N-\bar{x}^2=2048/22-64\approx29.09$.
$\sigma^2=2048/22-64\approx29$.
Correct Answer: 29