Four students each measured the density of a metal three times (see results given below). Which data set is the most precise? Which set is the least precise? Explain your answer. The actual density of the metal is 7.847 g/mL.

Student 1: 7.835, 7.859, and 7.845 g/mL

Student 2: 7.847, 7.857, and 7.859 g/mL

Student 3: 7.82, 7.82, and 7.83 g/mL

Student 4: 7.813, 7.817, and 7.816 g/mL