Inexactnes or Inexactness: How To spell?
The word Inexactnes is misspelled against Inexactness, a noun meaning "Incorrectness; want of exactness."
Inexactness has double 'ss' in the end mispronounced as 's'Remember double 'SS' appears in the end of this word which should not be misspelled with single 'S'
Wrong Spelling:  inexactne-s  Correct Spelling:  inexactne-ss 
Explore spell check of Inexactness to spell without errors.