The regression line of \(y\) on \(x\), obtained from a random sample of five pairs of values of \(x\) and \(y\), has equation
$$y = x + k$$
where \(k\) is a constant. The following table shows the data.
Find the two possible values of \(p\).
For the smaller of these two values of \(p\), find
- the product moment correlation coefficient,
- the equation of the regression line of \(x\) on \(y\).