## Solution

The output from FFT Power Spectrum and PSD.vi is a cluster containing two double precision elements, and a double precision array:

*f0*: Starting Frequency*df*: Frequency Resolution*Magnitude*: Array of Power values for each frequency

In order to find the fundamental frequency we first need to find the largest power/amplitude within

*Magnitude *and its index in the array. The index then be can used with *f0 *and *df *as shown in the following equation to find the fundamental frequency.*Fundamental Frequency = Index of Largest Power x Frequency Resolution(df) + Starting Frequency(f0)* The following code shows how the cluster can be used to find the fundamental frequency: