boon/src/main/java/org/boon/primitive/Lng.java
public static double meanDouble( long[] values, final int start, final int length ) {
        double mean = ((double)sum(values, start, length))/ ((double) length);
        return mean;
    }
public static double meanDouble( long[] values, final int start, final int length ) {
        double mean = ((double)sum(values, start, length))/ ((double) length);
        return mean;
    }
Used internally to avoid loss and rounding errors a bit.
@param values values
@param start start
@param length length
@return meanDouble