prove out vs put to the test

prove out

verb
  • To demonstrate the feasibility of; to show or be shown to be feasible, accurate, true, satisfactory, as expected, hoped, stated, etc. 

  • To turn out to be feasible, accurate, true, satisfactory, as expected, hoped, stated, etc. 

put to the test

verb
  • To test something or someone; to evaluate, scrutinize or explore by testing or experimentation. 

How often have the words prove out and put to the test occurred in a corpus of books? (source: Google Ngram Viewer )