t, 2 and F probability distributions are widely used in statistics. Draw an example of each of the three distributions (t, 2 and F) with labelled axes. Explain the basis of each distribution and how each can be used in statistical tests. [12 marks]

b Explain what is meant by the term 'power of a statistical test'. Discuss the approaches that can be used to increase the power of statistical tests and the advantages and disadvantages of each approach