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.
It is so fast that light can travel about seven times around Earth in one second!! Thatâs about light. What is a light year then? Light Year is the distance that light can travel in one year. Considering that light can travel about 300,000 kilometers (km) each second, in one year, it can travel 9,500,000,000,000 kilometers. Phew! It would be easier to say that one light year is about 10 trillion km.