What was found
Flt 707 from DEN to TOL. During cruise level at FL 330 #3 engine flame out. Oil pressure and quantity as well as N1 and N2 were normal. Descended to two engine cruise altitude and conducted engine failure shutdown checklist and all indications were normal, attempted one engine restart without success. Notified ATC, continue to Toledo. Declared an emergency with Toledo approach as a precaution and landed without incident. Investigation found the #3 engine driven fuel pump shaft sheared. Replaced the #3 fuel pump, engine run and leak check good IAW MM 73-11-1 and 71-00-117. Aircraft returned to service.