AQA Further Paper 3 Statistics 2020 June — Question 4

Exam BoardAQA
ModuleFurther Paper 3 Statistics (Further Paper 3 Statistics)
Year2020
SessionJune
TopicUniform Distribution
TypeVariance of linear transformation

4 The discrete random variable \(X\) follows a discrete uniform distribution and takes values \(1,2,3 , \ldots , n\). The discrete random variable \(Y\) is defined by \(Y = 2 X\)
4
  1. Using the standard results for \(\sum n , \sum n ^ { 2 }\) and \(\operatorname { Var } ( a X + b )\), prove that $$\operatorname { Var } ( Y ) = \frac { n ^ { 2 } - 1 } { 3 }$$ 4
  2. A spinning toy can land on one of four values: 2, 4, 6 or 8
    Using a discrete uniform distribution, find the probability that the next value the toy lands on is greater than 2 4
  3. State an assumption that is required for the discrete uniform distribution used in part (b) to be valid.