Calculates the total mathematical area under the curve from negative infinity up to a specific x value. Expressed formally as P(X < x).

Represents the area greater than a specific value, continuing towards positive infinity. It represents the inverse remainder of a Left Tail equation: P(X > x) = 1 - P(X < x).

Finds the exclusive probability of an event landing strictly between two established bounds, x1 and x2. Represents the core mass of the bell curve.

The total probability of an outcome landing in either extreme tail (less than x1 OR greater than x2), completely ignoring the middle distribution section.