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 is the distance that light can travel in a year, or: 186,000 miles/second * 60 seconds/minute * 60 minutes/hour * 24 hours/day * 365 days/year = 5,865,696,000,000 miles/year. A light year is 5,865,696,000,000 miles (9,460,800,000,000 kilometers). That's a long way! Using a light year as a distance measurement has another advantage -- it helps you determine age. Let's say that a star is 1 million light years away. The light from that star has traveled at the speed of light to reach us.