Well, I figured out the different data types for DBMS_SQL columns. You do not specify the 4th parameter [data length] for non-character data in the DMBS_SQL.DEFINE_COLUMN statements.

  PROCEDURE Retrieve_Facilities (v_Query VARCHAR2)
   IS
      < snip >

      /* numeric data type for KeyID */
      v_KeyID         Inquiry_View.KeyID%Type;

   BEGIN

      < snip > 

      DBMS_SQL.DEFINE_COLUMN(v_cursor_id, 5, v_KeyID);