function skewness( N, K, n ) {
	var p;
	var q;
	if (
		!isNonNegativeInteger( N ) ||
		!isNonNegativeInteger( K ) ||
		!isNonNegativeInteger( n ) ||
		N === PINF ||
		K === PINF ||
		K > N ||
		n > N
	) {
		return NaN;
	}
	p = ( N - (2*K) ) * sqrt( N - 1 ) * ( N - (2*n) );
	q = sqrt( n * K * ( N-K ) * ( N-n ) ) * ( N - 2 );
	return p / q;
}
Returns the skewness of a hypergeometric distribution.

@param {NonNegativeInteger} N - population size
@param {NonNegativeInteger} K - subpopulation size
@param {NonNegativeInteger} n - number of draws
@returns {number} skewness

@example
var v = skewness( 16, 11, 4 );
// returns ~-0.258

@example
var v = skewness( 4, 2, 2 );
// returns 0.0

@example
var v = skewness( 10, 5, 12 );
// returns NaN

@example
var v = skewness( 10.3, 10, 4 );
// returns NaN

@example
var v = skewness( 10, 5.5, 4 );
// returns NaN

@example
var v = skewness( 10, 5, 4.5 );
// returns NaN

@example
var v = skewness( NaN, 10, 4 );
// returns NaN

@example
var v = skewness( 20, NaN, 4 );
// returns NaN

@example
var v = skewness( 20, 10, NaN );
// returns NaN