Median

The median is one of the location parameters in probability theory and statistics. (The others are the mean and the mode.) For a real valued random variable X with a cumulative distribution function F, the median of X is the unique number that satisfies . In other words, the median is the number that separates the upper half from the lower half of a population or a sample. If a random variable is continuous and has a probability density function, half of the area under the probability density function curve would be to the left of m and the other half to the right of m. For this reason, the median is also called the 50th percentile (the ith percentile is the value such that ...