A package filled with 60 donated clothing items was just dropped off.
1/5 of the items in the package were shirts.
0.45 of the items in the package were jeans.
The rest of the items in the package were dresses.
How many dresses were in the package?
The number of shirts in the package is (1/5) * 60 = <<(1/5)*60=12>>12.
The number of jeans in the package is 0.45 * 60 = <<0.45*60=27>>27.
The total number of shirts and jeans is 12 + 27 = <<12+27=39>>39.
The number of dresses in the package is 60 - 39 = <<60-39=21>>21. Answer: \boxed{21}.