(a) draw a scatter diagram of the data,
(b) by hand, compute the correlation coefficient, and
(c) determine whether there is a linear relation between $x$ and $y$
$$\begin{array}{cccccc}
x & 2 & 3 & 5 & 6 & 6 \\
\hline y & 10 & 9 & 7 & 4 & 2
\end{array}$$