The capital Greek letter (capital mu) is visually very similar to the uppercase Latin letter M. For that reason, refer to the usage of Capital M for how the symbol appears in math.
Symbol  Format  Data 

Μ  Unicode 

TeX 


SVG 
The Greek Alphabet is used throughout math to represent variables, constants, and coeffecients within math expressions, formulas, and equations.
The Greek letter μ (mu) is used in statistics to represent the population mean of a distribution.