Collecting this data into a frequency distribution gives
Table 1.6.2. Grouped Discrete Data
\(x_k\) \(f_k\)
1 5
2 7
3 4
4 3
5 6
Therefore,
\begin{equation*} \overline{x} = \frac{1 \times 5 + 2 \times 7 + 3 \times 4 + 4 \times 3 + 5 \times 6}{5+7+4+3+6} \\ = \frac{5 + 14 + 12 + 12 + 30}{25} = \frac{43}{25} \end{equation*}
and
\begin{align*} v & = \frac{1^2 \times 5 + 2^2 \times 7 + 3^2 \times 4 + 4^2 \times 3 + 5^2 \times 6}{5+7+4+3+6} - \left ( \frac{43}{25} \right )^2 \\ & = \frac{5 + 28 + 36 + 48 + 150}{25} - \left ( \frac{43}{25} \right )^2 \\ & = \frac{4826}{625}\\ & \approx 7.7216 \end{align*}
and so \(s^2 = \frac{25}{24} \frac{4826}{625} \approx 8.043\text{.}\)