A measurement using a geiger counter on an carbon-based artifact gave 11.1 disintegrations of C-14 per minute per gram of carbon. Carbon from living materials gives 15.3 disintegrations per minute per gram of carbon. The half life of C-14 is 5730 years. If you use scientific notation, report your answer in the following form: 5.50E3 = 5500 years. The age of the artifact is estimated at how many years?