The table below shows the monthly returns yielded by Securities W and Z during 2018, together with those for the market as a whole. Security return (%) Month W z Market January 3 6 5 February 5 3 9 March 3 5 2 April -12 -10 -12 May 4 -5 0 June 0 8 11 July -5 0 -8 August 5 -4 3 September 0 2 October 3 0 -5 -7 November -1 12 2 December 7 1 Use the above data to calculate: (i) the sample mean and variance of the monthly return for each of the securities and the market as a whole. [2 marks] (ii) the sample covariance of returns between the two securities. [2 Marks] (iii) the sample covariance of returns between each security and the market, and hence the sample beta of each security. [6 Marks)