How is the kurtosis calculation algorithm made?

Hi :D.

I want to analyze the Ultrasonic signal data using kurtosis.

i saw the kurtosis calculation algorithm at the matlab homepage.

I know that this cultus is calculated based on the histogram.

But I don't know the Histogram bin value.

1. Is it just calculating the kurtosis using the BIN value of the graph above?
2. There is an empty part in the graph. Do Kurtosis function also calculate the empty part?

I used the attached data.

Thank you!