Mean, Mode, Median, and Standard Deviation The Mean and Mode The sample mean is the average and is computed as the sum of all the observed outcomes from the sample divided by the total number of events. We use x as the symbol for the sample mean. In math terms, where n is the sample size and the x correspond to the observed valued . Example Suppose you randomly sampled six acres in the Desolation Wilderness for a non-indigenous weed and came up with the following counts of this weed in this region: 34, 43, 81, 106, 106 and 115 We compute the sample mean by adding and dividing by the number of samples, 6. 34 + 43 + 81 + 106 + 106 + 115 ...