Because we're creating a 95% confidence interval, this means we have two tails of 2.5%. When we look up 0.025 in the Z table (click to open) , we find that it corresponds to a z-score of 1.96. After plugging everything into the equation, we find a lower bound of 480.8 and an upper bound of 559.2.
As already noted, the speed of light (expressed in meters per second) means that light travels a distance of 9,460,528,000,000 km (or 5,878,499,817,000 miles) in a single year. This distance is known as a âlight yearâ, and is used to measure objects in the Universe that are at a considerable distances from us.
A light year, abbreviated ly, is the distance light travels in one year: roughly 9.46 Ã 1012 kilometres (9.46 petametres, or about 5.88 Ã 1012 (nearly six trillion) miles). More specifically, a light year is defined as the distance that a photon would travel, in free space and infinitely far away from any gravitational or magnetic fields, in one Julian year (365.25 days of 86400 seconds each).