Interogatory or Interrogatory: How To spell?
The word Interogatory is misspelled against Interrogatory, a noun meaning "A formal question or inquiry; esp. (Law), a question asked in writing."
Interrogatory has double "rr" is mispronounced as "r"Remember double 'RR' in between the strings inte & ogatory which should not be misspelled with single 'R'
Wrong Spelling:  inte-r-ogatory  Correct Spelling:  inte-rr-ogatory 
Find more incorrect spellings of Interrogatory to spell right way.