MEAN inputVector resultVariable

Replaces the contents of the result variable with the mean (average) of the elements of the input vector. If the input vector has any missing data (represented by "." or "NaN"), they are removed before the mean is calculated.

COPY 1,10 A
MEAN A mean
PRINT A mean 

The above program produces the following output:

A: (1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0)
mean: 5.5