Probability and Odds

Before we move on to work with logistic regression, we must clearly understand these essential statistical concepts.

Probability

Probability describes the likeliness of some event happening or occurring on a numerical scale between 0 (impossible) and 1 (sure). The higher the probability is, the more likely the event will occur. Tossing a fair coin or rolling a dice and expecting how often we’ll get heads or a certain number on a dice is simply the outcome divided by the total options or possibilities.

In the case of a fair coin, the probability of getting heads or tails is the same, $\frac{1}{2}$ (0.5 or 50% chance). Similarly, for the dice, the chance of getting a certain number is $\frac{1}{6}$ ...