Suppose you are trying to determine if the population means of groups A, B and C are the same or different. You take three samples and find that the sample means of groups A, B and C are 2.5, 3.1 and 1.9, respectively.

What can you conclude about the population means of the groups?

Conclude that the population means are different because the sample means are different.
You cannot make a conclusion about the population means based only on the sample means. You need to conduct a statistical test.