numerical_comparison/com/innovanon/sjp/numerical_comparison/Stats.java
/**
	 * @return average if it's defined; null otherwise
	 */
@return average if it's defined; null otherwise
@return average if it ' s defined ; null otherwise
public Double arithmetic_mean () {
		int n = this.args.length;
		if (n == 0) return null;
		double ret = (double) this.sum () / n;
		return Double.valueOf (ret);
	}
public Double arithmetic_mean ( ) { int n = this . args . length ; if ( n == 0 ) return null ; double ret = ( double ) this . sum ( ) / n ; return Double . valueOf ( ret ) ; }
@return average if it's defined; null otherwise
@return average if it ' s defined ; null otherwise