Probability and Statistics: The difference

Have you ever pondered what makes probability different from statistics

Probability and statistics are core topics in Data Science which are studied together.But many of us fail to understand difference between the two. This blog will try to highlight difference between them.

Suppose we perform an experiment of throwing a die. We can ask questions like:

• What is the probability that we will get a six?

• What is the probability of getting a number greater the two?

One thing to notice in the above is that both of them are asking question about a future event that has not happened. So probability tries to predict how likely an event will occur in near future.

Now take another scenario. Suppose we have the outcome of thousand throws of a die. Now based on the data of the outcome we ask the following questions:

• What is the proportion of six?

• What is the mean of the total outcome?

• Looking at the outcome, can you tell whether the die is biased or not?

The above questions ask about things that has already occurred in past. These question seek to get answers from the past data. So statistics deals with data of some past events and try to get answers from those data. Probability can use the inference of statistics to predict similar event.

So to summarize the difference: Probability vs Statistics is equivalent to Future vs Past.