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# Root Mean Square(RMS)/Quadratic Mean(QM) Tutorial

## Root Mean Square(RMS)/Quadratic Mean(QM) Tutorial

##### Root Mean Square(RMS)/Quadratic Mean(QM) Definition:

Square root of the mean square value of a random variable. In otherwords, we can define the root mean square is a statistical measure of the magnitude of a varying quantity. It can be calculated for a series of discrete values or for a continuously varying function. It is also known as Quadratic Mean(QM).

#### Root Mean Square/Quadratic Mean Formula:

Root Mean Square/Quadratic Mean = Sqrt((X1)2+(X2)2+(X3)2+........+(XN)2/N) Where,

X = Individual score N = Sample size (Number of scores)

##### Root Mean Square(RMS) Example:

To find the Root Mean Square of -2,-1,-3,1,5.

###### Step 1:

Count the total number of values. N = 5

###### Step 2:

Square all the values. 4,1,9,1,25

###### Step 3:

Take the average of the square values. 4+1+9+1+25/5 = 40/5 = 8

###### Step 4:

Take the square root of the average values. RMS/QM = sqrt(8) = 2.83 This example will guide you to calculate the Root mean square/Quadratic Mean manually.