Three liquids are at temperatures of 5 ◦C, 25◦C, and 34◦C, respectively. Equal masses of the first two liquids are mixed, and the equilibrium temperature is 17◦C. Equal masses of the second and third are then mixed, and the equilibrium temperature is 30.7 ◦C. Find the equilibrium temperature when equal masses of the first and third are mixed. Answer in units of ◦C.