Choose co-suffix for (1, 6), (2, 9), (3, 6), (4,7), (5, 8), (6, 5), (7, 12), (8, 3), (9, 17), (10, 1)-

Explanation

$$ \begin{aligned} \overline{x} &= \frac{1+2+3+4+5+6+7+8+9+10}{10} \\ \\ &= 5.5 \\ \overline{y} &= \frac{6+9+6+7+8+5+12+3+17+1}{10} \\ &= 7.4 \\ n &= 10 \\ \sum(x-\overline{x})(y-\overline{y}) &= 4.0 \\ (\sigma)^2 &= \frac{1}{n}\sum(x-\overline{x})(y-\overline{y}) = \frac{1}{10} \times 4 \\ 4 \\ &= 0.4 \end{aligned} $$