What are the merits and demerits of arithmetic mean?

Answer 1

Arithmetic mean (the average) of a series of values can gives us a fairly decent estimate of the most probable value of a next input. For example in the group: 0, 3, 4, 6, 7, 7, 8 The average is 5. This gives us a good estimate of what we should expect a value to be. However, 5 does not appear even once in the group of values. The mean is not good for finding the most used value, the middle value, or dealing with extremes (numbers much higher or lower than most numbers in the group). Other statistical terms that can help add clarification to the mean are the median (middle number), mode (the most frequent number), and the range (the positive difference between the highest and lowest values).