Why is a person’s weight a continuous random variable?
Swiss commemorative stamp of mathematician Jakob Bernoulli, issued 1994, displaying the formula and the graph for the law of large numbers, first proved by Bernoulli in 1713.
A person’s weight is considered a continuous random variable because it can assume any value within an interval on the real number line.1
Unlike a discrete random variable, which is limited to a finite number of values or an infinite sequence of distinct values, a continuous random variable can take on an infinite number of possible values within a given range. Because there are infinitely many values in any such interval, it is not meaningful to assign a probability to a person weighing an exact, specific value (such as exactly 70.000... kg). Instead, in statistics, we calculate the probability that a person's weight falls within a specific range by using a probability density function and computing the integral over that interval.21