By mid point equation, x = 2, y = 0.5, the answer is 0.5
<span>"Because the Earth is spherical in shape, the areas between the Poles and the Equator benefit from solar energy to different extents over the year. Those areas on the Equator receive the highest levels of solar energy, and that energy declines towards the Poles. The temperatures of atmospheric masses thus differ as one moves from the Equator to the Poles." (http://assandra-sciences.blogspot.com/2010/07/how-does-shape-of-earth-affect-climate.html)
</span>
<span>An eon is a geologically around tens of millions of years. A period is a million year included in an eon which is also made up of several eras. Therefore my answer is a period due to it being a subset of an era which is a subset of an eon.</span>
