3. Consider a single-component system held at constant T and P in the isothermal-isobaric ensemble. (a) Show how the compressibility T relates to the average volume, V, and volume fluctuations v2=V2V2. (b) For a single-phase system, how do the fluctuations in volume scale with system size N? (c) Consider a certain T and P where the system can coexist as both a liquid and a vapor. How do fluctuations in volume scale with the system size in this case? What does this tell you about the compressibility as N becomes large