Random Variable

AAA

DEFINITION of 'Random Variable'

A variable whose value is unknown or a function that assigns values to each of an experiment's outcomes. Random variables are often designated by letters and can be classified as discrete, which are variables that have specific values, or continuous, which are variables that can have any values within a continuous range.

INVESTOPEDIA EXPLAINS 'Random Variable'

Consider an experiment where a coin is tossed three times. If X represents the number of times that the coin comes up heads, then X is a discrete random variable that can only have the values 0,1,2,3 (from no heads in three successive coin tosses, to all heads). No other value is possible for X.


An example of a continuous random variable would be an experiment that involves measuring the amount of rainfall in a city over a year, or the average height of a random group of 25 people.




RELATED TERMS
  1. Discrete Distribution

    The statistical or probabilistic properties of observable (either ...
  2. Nonparametric Statistics

    A statistical method wherein the data is not required to fit ...
  3. Normal Distribution

    A probability distribution that plots all of its values in a ...
  4. Probability Distribution

    A statistical function that describes all the possible values ...
  5. Scenario Analysis

    The process of estimating the expected value of a portfolio after ...
  6. Sharpe Ratio

    A ratio developed by Nobel laureate William F. Sharpe to measure ...
RELATED FAQS
  1. What is the variance/covariance matrix or parametric method in Value at Risk (VaR)?

    The parametric method, also known as the variance-covariance method, is a risk management technique for calculating the value ... Read Full Answer >>
  2. What is backtesting in Value at Risk (VaR)?

    The value at risk is a statistical risk management technique that monitors and quantifies the risk level associated with ... Read Full Answer >>
  3. How much variance should an investor have in an indexed fund?

    An investor should have as much variance in an indexed fund as he is comfortable with. Variance is the measure of the spread ... Read Full Answer >>
  4. Can the correlation coefficient be used to measure dependence?

    The correlation coefficient can be used to measure the linear dependence between two random variables. The most common correlation ... Read Full Answer >>
  5. How do you calculate variance in Excel?

    To calculate statistical variance in Microsoft Excel, use the built-in Excel function VAR. Given a set of numbers value1 ... Read Full Answer >>
  6. How do I discount Free Cash Flow to the Firm (FCFF)?

    Discounted free cash flow for the firm (FCFF) should be equal to all of the cash inflows and outflows, adjusted to present ... Read Full Answer >>
Related Articles
  1. Investing Basics

    What Are The Odds Of Scoring A Winning Trade?

    Just because you're on a winning streak doesn't mean you're a skilled trader. Find out why.
  2. Fundamental Analysis

    Financial Markets: Random, Cyclical Or Both?

    Are the markets random or cyclical? It depends on who you ask. Here, we go over both sides of the argument.
  3. Forex Education

    Trading With Gaussian Models Of Statistics

    The entire study of statistics originated from Gauss and allowed us to understand markets, prices and probabilities, among other applications.
  4. Trading Strategies

    What Your Trading Charts Aren't Telling You

    You may be missing some key statistics when following charts in the market.
  5. Fundamental Analysis

    Explaining Expected Return

    The expected return is a tool used to determine whether or not an investment has a positive or negative average net outcome.
  6. Economics

    Understanding the Fisher Effect

    The Fisher effect states that the real interest rate equals the nominal interest rate minus the expected inflation rate.
  7. Fundamental Analysis

    Explaining the Geometric Mean

    The average of a set of products, the calculation of which is commonly used to determine the performance results of an investment or portfolio.
  8. Investing

    The Labor Market Recovery’s Missing Ingredient

    Job creation is running at the fastest pace since the 90s, and there is some evidence that wage growth is finally starting to accelerate, albeit modestly.
  9. Trading Strategies

    Best Undergraduate Degrees For Day Traders

    We look at some popular undergrad majors for those wanting to begin a career in the exciting world of fast-paced trading.
  10. Fundamental Analysis

    Explaining Standard Error

    Standard error is a statistical term that measures the accuracy with which a sample represents a population.

You May Also Like

Hot Definitions
  1. Venture-Capital-Backed IPO

    The selling to the public of shares in a company that has previously been funded primarily by private investors. The alternative ...
  2. Merger Arbitrage

    A hedge fund strategy in which the stocks of two merging companies are simultaneously bought and sold to create a riskless ...
  3. Market Failure

    An economic term that encompasses a situation where, in any given market, the quantity of a product demanded by consumers ...
  4. Unsystematic Risk

    Company or industry specific risk that is inherent in each investment. The amount of unsystematic risk can be reduced through ...
  5. Security Market Line - SML

    A line that graphs the systematic, or market, risk versus return of the whole market at a certain time and shows all risky ...
  6. Tangible Net Worth

    A measure of the physical worth of a company, which does not include any value derived from intangible assets such as copyrights, ...
Trading Center