ARRAY. Each value is given a weight of 1. The total weight
is stored into *WEIGHT (trivially) and the mean, variance,
skewness, and kurtosis are stored into *MEAN, *VARIANCE,
*SKEWNESS, and *KURTOSIS, respectively. Any of the result
pointers may be null, in which case no value is stored. */
void
ARRAY. Each value is given a weight of 1. The total weight
is stored into *WEIGHT (trivially) and the mean, variance,
skewness, and kurtosis are stored into *MEAN, *VARIANCE,
*SKEWNESS, and *KURTOSIS, respectively. Any of the result
pointers may be null, in which case no value is stored. */
void