Which parallel lies midway between these two lines of tropic or cancer and the tropic of Capricorn and why?

The parallel that lies midway between the Tropic of Cancer and the Tropic of Capricorn is the Equator. This is because the Tropic of Cancer is located at approximately 23.5° North latitude, and the Tropic of Capricorn is at approximately 23.5° South latitude. The Equator, situated at 0° latitude, represents the midpoint between these two tropics, dividing the Earth into the Northern and Southern Hemispheres.