FIR and IIR are digital filters that are commonly used in digital signal processing. There are only a few components that make up these filters, but these components can be arranged in various ways to make complicated filters for use in digital signal processing.
In some statistical analyses, the median is a better predictor of the expected value for a set of observations than the mean (average). To calculate the median, in the simplest terms, if you have an odd number (n) of items in an ordered set, the median is the value where (n+1)/2 is the row containing the median value. If there is an even number of rows, the value is the average (mean) of the two values appearing in the n/2 and the 1+n/2 rows.
Median is the number in the exact middle of the data set once the data set is put in the order of least to greatest value. If the number of numbers in the data set is even, and there are two medians, then you would find the mean of the median to get your true median. Here is an example.