Calculate Quality (x) and Specific Volume (v) in mixed Phase (Mixture) | Examples | Thermodynamics 

Are you talking about how to calculate quality, i.e. the percentage and the volume of liquid and vapor? Try the video below. If that is still not what you are looking for, you can type in your problem with the description and I will see what you are looking for. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-PqhjP2m6msc.html

320 kPa is a known from the problem description. The problem gives the temperature at -12 degree and pressure at 320 kPa.

The numbers are sllightly different bewteen books. I would consider 0.037452 and 0.037408 smilar and both correct.