Noun
quadratic mean (plural quadratic means)
(mathematics) A type of average, calculated as the square root of the mean of the squares, ie.
Q
=
x
1
2
+
x
2
2
+
.
.
.
+
x
n
2
n
{\displaystyle Q={\sqrt {x_{1}^{2}+x_{2}^{2}+...+x_{n}^{2} \over n}}}
.