4 The probability distribution of the random variable \(X\) is given by the formula
$$\mathrm { P } ( X = r ) = \frac { k } { r ( r - 1 ) } \text { for } r = 2,3,4,5,6 .$$
- Show that the value of \(k\) is 1.2 . Using this value of \(k\), show the probability distribution of \(X\) in a table.
- Find \(\mathrm { E } ( X )\) and \(\operatorname { Var } ( X )\).