OCR MEI S1 2014 June — Question 5

Exam BoardOCR MEI
ModuleS1 (Statistics 1)
Year2014
SessionJune
TopicDiscrete Probability Distributions
TypeSimple algebraic expression for P(X=x)

5 The probability distribution of the random variable \(X\) is given by the formula $$\mathrm { P } ( X = r ) = k + 0.01 r ^ { 2 } \text { for } r = 1,2,3,4,5 \text {. }$$
  1. Show that \(k = 0.09\). Using this value of \(k\), display the probability distribution of \(X\) in a table.
  2. Find \(\mathrm { E } ( X )\) and \(\operatorname { Var } ( X )\).