Calculate the variance of a Net Promoter Score
This function calculates the Net Promoter Score variance, taking a
vector of length three, with numbers or proportions of Detractors, Passives, and Promoters, respectively.
numeric. The variance of the distribution, ranging from 0 to 1.
Brendan Rocks firstname.lastname@example.org
nps.var, a version which works on raw Recommend responses