9 A set of 20 pairs of bivariate data \(( x , y )\) is summarised by
$$\Sigma x = 200 , \quad \Sigma x ^ { 2 } = 2125 , \quad \Sigma y = 240 , \quad \Sigma y ^ { 2 } = 8245 .$$
The product moment correlation coefficient is - 0.992 .
- What does the value of the product moment correlation coefficient indicate about a scatter diagram of the data points?
- Find the equation of the regression line of \(y\) on \(x\).
- The equation of the regression line of \(x\) on \(y\) is \(x = a ^ { \prime } + b ^ { \prime } y\). Find the value of \(b ^ { \prime }\).