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Root Mean Square

Root Mean Square
RMS

A kind of average sometimes used in statistics and engineering, often abbreviated as RMS. To find the root mean square of a set of numbers, square all the numbers in the set and then find the arithmetic mean of the squares. Take the square root of the result. This is the root mean square.

 

Formula: RMS formula: RMS = sqrt((a₁² + a₂² + a₃² + ··· + aₙ²) / n)   or   Square root of (sum from i=1 to n of a_i squared, divided by n)
Example:

For the numbers 4 and 9,

RMS formula: RMS = sqrt((4² + 9²) / 2) ≈ 6.96, showing example calculation with numbers 4 and 9.

 

See also

Mean