4 Experimental data given in blue Complete the following based on the given data: 1. Find the average background radiation Minute 1 12 Minute 2 20 Minute 3 17 Minute 4 23 Minute 5 27 Average 19.8 (This will be your background for one minute.) Complete the table: Remember that you have to subtract your background from your measurement to find the radiation of the source and complete the table. Item tested Measurement (CPM) Average Source Type of radiation Background if known Thallium-204 2970 19.8 2950,2 beta Cobalt-60 1035 19.8 1015,2 gamma Cell phone 25 19.8 unknown 5,2 Notebook 19 19.8 -8 unknown