<prompt> In calculating crude bih rate which of the following is used as denominatorWomen in 15-49 yrs age groupAll persons in 15-49 yrs age groupMid year populationAll live bihs  <response>: Bih rate Number of live bihs during the year X 1000 Estimated mid year population Unsatisfactory measure of feility because the total population is not exposed to child bearing Reference : Park;s textbook of preventive and social medicine, 23rd edition, pg no: 488 