I have the answer for part b) for water it is 0.31 and ethanol 1.004 for c) yethanol=.95 So please I need to know how to work it out.

Exercise 2 An azeotropic mixture of ethanol and water, which contains 95.6 wt.\% of ethanol, boils at 78.15C. The vapor pressures of pure substances at this temperature are: p( ethanol) =100.9kPa,p (water) =43.86kPa. Based on these data: a) draw a pxy and y - x diagram at 78.15C; b) calculate the values of the activity coefficients of ethanol and water at the eutectic composition; c) determine the pressure and composition of the vapor phase, which would correspond to a liquid mixture with a content of 95.6wt% ethanol, assuming validity of the Raoult's law