boon/src/main/java/org/boon/primitive/Lng.java
public static long mean( long[] values, final int start, final int length ) {
        return (long) Math.round(meanDouble(values, start, length));
    }
public static long mean( long[] values, final int start, final int length ) {
        return (long) Math.round(meanDouble(values, start, length));
    }
Average
@param values values in int
@return average