the average or the mean is given by getting the sum of the total items in a given data and then dividing it with the number of items in the data. That is; the sum = 3.1 + 2.7 +4.6 + 1.9 + 8.7 = 21 number of values = 5 The average = 21/5 = 4.2 Thus, the correct answer is 4.2 mL