Eliminate infeasible step in exercise

joins.qmd

@@ -367,8 +367,7 @@ flights2 |>
 4.  What do the tail numbers that don't have a matching record in `planes` have in common?
     (Hint: one variable explains \~90% of the problems.)
 
-5.  Add a column to `planes` that lists every `carrier` that has flown that plane.
-    You might expect that there's an implicit relationship between plane and airline, because each plane is flown by a single airline.
+5.  You might expect that there's an implicit relationship between plane and airline, because each plane is flown by a single airline.
     Confirm or reject this hypothesis using the tools you've learned in previous chapters.
 
 6.  Add the latitude and the longitude of the origin *and* destination airport to `flights`.