<prompt> The number of aboions performed divided by the number of live bihs in the same period is known asAboion rateAboion incidenceAboion prevalenceAboion ratio  <response>: Aboion ratio is calculated by dividing the number of aboions performed during a paicular time period by the number of live bihs over the same period Reference : Park;s textbook of preventive and social medicine, 23rd edition, Page no: 489 