Merits:

• It is rigidly defined and its value is a precise figure.
• It is based on all observations.
• It is capable of further algebraic treatment.
• It is not much affected by fluctuation of sampling.
• It is not affected by extreme values.

Demerits:

• It cannot be calculated if any of the observation is zero or negative.
• Its calculation is rather difficult.
• It is not easy to understand.
• It may not coincide with any of the abservations.