   where airline.UniqueCarrier = airlineref.Code
   group by UniqueCarrier, description
   order by arrivalDelay
-  with error 0.07 confidence 0.90;
+  with error 0.20 confidence 0.80;
 
 -------------------------------------------------------------
 ---- What is the trend in arrival delays across all airlines in the US? ----

   where airline.UniqueCarrier = airlineref.code
   group by UniqueCarrier,description, Year_
   order by flightRecCount desc limit 10
   with error 0.07 confidence 0.82;

-------------------------------------------------------------
---- Which Airlines Arrive On Schedule? ----

select AVG(ArrDelay) arrivalDelay, absolute_error(arrivalDelay) abs_err, relative_error(arrivalDelay) rel_err, UniqueCarrier carrier from airline
   group by UniqueCarrier
   order by arrivalDelay
   with error 0.20 confidence 0.80;

-------------------------------------------------------------
---- Which Airlines Arrive On Schedule? JOIN with reference table ----
