Edexcel S3 2020 October — Question 1

Exam BoardEdexcel
ModuleS3 (Statistics 3)
Year2020
SessionOctober
TopicUniform Distribution
TypeFind parameter from variance or other constraint

  1. The random variable \(X\) has the discrete uniform distribution
$$\mathrm { P } ( X = x ) = \frac { 1 } { \alpha } \quad \text { for } x = 1,2 , \ldots , \alpha$$ The mean of a random sample of size \(n\), taken from this distribution, is denoted by \(\bar { X }\)
  1. Show that \(2 \bar { X }\) is a biased estimator of \(\alpha\) A random sample of 6 observations of \(X\) is taken and the results are given below. $$\begin{array} { l l l l l l } 8 & 7 & 3 & 7 & 2 & 9 \end{array}$$
  2. Use the sample mean to estimate the value of \(\alpha\)