The discrete - time transfer function of an Infinite Impulse Response ( IIR ) filter used in a biomedical application is given by  H ( z ) = ( z − 0 . 6 ) / ( z ^ 2 1 . 5 z 0 . 5 ) ( i ) Find the numerical value of the poles and zeros of the system. ( ii ) Sketch the pole - zero diagram for the system. ( iii ) State, with justification, whether the system is stable or not.