The mean is the most commonly used average.
To find the mean of a list of numbers, add them all together and divide by how many numbers there are:
7 babies weigh the following amounts:
2.5 kg, 3.1 kg, 3.4 kg, 3.5 kg, 3.5 kg, 4 kg, 4.1 kg
Find the mean mass of the babies.
The mean mass of the babies is 3.44 kg.