MEAN
MEAN The mean is the average of the numbers. It is easy to calculate: add up all the numbers, then divide by how many numbers there are. In other words it is the sum divided by the count. Types of means Pythagorean mean Arithmetic mean (AM) The arithmetic mean (or simply mean ) of a list of numbers, is the sum of all of the numbers divided by the number of numbers. Similarly, the mean of a sample {\displaystyle x_{1},x_{2},\ldots ,x_{n}} , usually denoted by {\displaystyle {\bar {x}}} , is the sum of the sampled values divided by the number of items in the sample {\displaystyle {\bar {x}}={\frac {1}{n}}\left(\sum _{i=1}^{n}{x_{i}}\right)={\frac {x_{1}+x_{2}+\cdots +x_{n}}{n}}} For example, the arithmetic mean of five values: 4, 36, 45, 50, 75 is: {\displaystyle {\frac {4+36+45+50+75}{5}}={\frac {210}{5}}=42.} Geometric mean (GM) The geometric mean is an average that is useful for sets of positive numbers, that are interpret...