Here,
N=50 and \(\displaystyle\sum f_ix_i\) = 3100
\(\bar{x}=\frac{1}{N}\displaystyle\sum_{i=1}^{7} f_ix_i\)
\(=\frac{3100}{50}\)
= 62
\(σ=\frac{1}{N}\displaystyle\sum_{i=1}^{7} f_i(x_i-\bar{x})^2\)
= \(\frac{1}{50} \times 10050\)
Standard deviation,
\(σ=\sqrt {201}\)
= 14.18
