A Doctor may have one or more Patients.
A Patient must have one and only one Doctor.

Questions
Which is the one and which is the many?
Which is the parent and which is the child?

Unnormalized Sample Data
Patient    Insurance   Room  Doctor     Specialty  Phone
Tweety     Red Cross   1201  Livingston GP         555-2376
Sylvester  Red Shield  1404  Kilder     Surgeon    555-9641
Ralph      Silver Plan 1409  Livingston GP         555-2376
Kim        Red Cross   1414  Livingston GP         555-2376
Tommy      ABC Ins     1212  Spock      GP         555-0358
Jill       Silver Plan 1201  Kilder     Surgeon    555-9641
Pat        ABC Ins     1404  Casey      Internal   555-9641
Sally      Red Shield  1414  Spock      GP         555-0358

Where do we add the foreign key?

Sample Patient Data
Patient    Insurance   Room
Tweety     Red Cross   1201
Sylvester  Red Shield  1404
Ralph      Silver Plan 1409
Kim        Red Cross   1414
Tommy      ABC Ins     1212
Jill       Silver Plan 1201
Pat        ABC Ins     1404
Sally      Red Shield  1414
 

Sample Doctor Data
Doctor      Specialty    Phone
Livingston  GP           555-2376
Kilder      Surgeon      555-9641
Casey       Internal     555-9641
Spock       GP           555-0358