A student took several trials to measure the boiling point value of water. The results are listed below. How many trials and which trials should be discarded to make the data precise? Trial 1: 100.1 Trial 2: 99.9 Trial 3: 100.2 Trial 4: 96.5 Trial 5: 100.0 Trial 6: 99.9 Trial 7: 107.5