1. A radio frequency identification (RFID) system for monitoring a space, the system comprising: a controller connected to a plurality of RFID readers, each reader configured to detect data signals from a plurality of RFID tags attached with objects, wherein the objects are of an object category; a database operatively connected with the controller and constructed to record: (1) a time when the data signal is received from each tag in the plurality; and (2) the data contained in the data signal from each tag in the plurality; and a processor operatively connected with the controller and configured to perform an inventory analysis of the objects based on a confidence probability curve wherein the processor is further configured to: calculate an in-store probability for each RFID tag in the plurality based on the confidence probability curve and the time for each RFID tag; and sum the in-store probabilities.