For a random sample of 10 observations of pairs of values \((x, y)\), the equation of the regression line of \(y\) on \(x\) is \(y=1.1664+0.4604 x\). It is given that
\[\Sigma x^{2}=1419.98 \quad \text { and } \quad \Sigma y^{2}=439.68 .\]

The mean value of \(y\) is 6.24 .
(i) Find the equation of the regression line of \(x\) on \(y\).
(ii) Find the product moment correlation coefficient.
(iii) Test at the \(5 \%\) significance level whether there is evidence of positive correlation between the two variables.