Question

What is the difference between at least and at most

Answer 1

At most means maximum, whereas at least means minimum
Let me explain with the help of an example.

Suppose that X takes values 0, 1, 2, 3 . . . . . . 6 with certain probabilities and we have to calculate the probability that:

X is at least 4
X is at most 4
Then:

In the first point, the phrase ‘X is at least 4’ means that the least X is allowed to be is 4; it can be 4, or any number greater than 4.

Similarly, In the second point, the phrase ‘X is at most 4’ means that the most X is allowed to be is 4; it can be 4, or any number less than 4.