The correct answer is D. all of the mentioned.
A random variable is a variable whose value is determined by chance. It is also called a stochastic variable or aleatory variable. The term “stochast” is a Greek word meaning “chance” or “fortune”. The term “aleatory” is a Latin word meaning “of or relating to chance”.
A random variable can be discrete or continuous. A discrete random variable can take on only a finite or countable number of values. A continuous random variable can take on any value in an interval.
The probability distribution of a random variable is a function that gives the probability of each possible value of the random variable. The mean of a random variable is the sum of the values of the random variable multiplied by their probabilities. The variance of a random variable is a measure of how spread out the values of the random variable are.
Random variables are used in many areas of mathematics, statistics, and physics. They are also used in many real-world applications, such as gambling, insurance, and finance.