Neliökeskiarvo

Neliökeskiarvo, also known as the root mean square (RMS), is a statistical measure. It is calculated by taking the square root of the average of the squares of a set of values. The formula for the neliökeskiarvo of a set of numbers x₁, x₂, ..., xₙ is √((x₁² + x₂² + ... + xₙ²)/n).

This measure is particularly useful when dealing with values that can be positive or negative, as squaring the values before averaging ensures that all contributions are positive. It gives more weight to larger values compared to a simple arithmetic mean.

Neliökeskiarvo finds applications in various fields. In electrical engineering, it is used to describe the effective value of an alternating current (AC) or voltage. In physics, it can be used to calculate the speed of particles in a gas, where individual particle speeds vary greatly. It is also employed in signal processing, mechanics, and other areas where the magnitude of varying quantities is important, regardless of their direction or sign. The neliökeskiarvo is always greater than or equal to the arithmetic mean of the absolute values of the data.