# Can expectation value be negative?

Expected value can be negative. However, a negative expected value is only possible if some of the data or outcomes have negative values. This is because probabilities are never negative. Of course, expected value can also be positive or zero.

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## Can expectation value be negative? – Everything you should know

• ### What happens when expected value is negative?

HOWEVER, if you were to calculate the expected value, for example, rolling a die, assuming landing on a 1 will take away 5 points, and anything else gives you no points. Therefore your expected value will be negative. Therefore meaning you will LOSE money and the house should gain money
• ### Can expected value be less than 1?

No. It cannot be more than 1. Observe that if a random variable X is less than or equal to 1 almost surely then certainly E(X) is less than or equal to 1.
• ### Can mean of random variable be negative?

All Answers (8) Yes, they can be negative Consider the following game. A fair 4-sided die, with the numbers 1; 2; 3; 4 is rolled twice.
• ### Which variables Cannot be negative?

the expected value of a random variable can never be negative.
• ### What if expected value is positive?

Expected Value (EV) is the average return on each dollar invested into a pot. If a player can expect, given probability to make more money than he or she bets, the action is said to have a positive expectation (+EV).
• ### How do you interpret an expected value?

In statistics and probability analysis, the expected value is calculated by multiplying each of the possible outcomes by the likelihood each outcome will occur and then summing all of those values. By calculating expected values, investors can choose the scenario most likely to give the desired outcome.
• ### Can expected value be zero?

Answer and Explanation: The expected value of any experiment can be zero but it does not mean that its real outcome will be zero.
• ### Is the expected value always the mean?

The only difference between “mean” and “expected value” is that mean is mainly used for frequency distribution and expectation is used for probability distribution. In frequency distribution, sample space consists of variables and their frequencies of occurrence.
• ### Which variables can never be negative in operations research?

Solution : The variables of objective function of the LPP can never take negative values, therefore these variables are zero or positive.
• ### Can expected value be infinite?

It is not surprising that the expected value is infinite when infinity is a possible value. However, the expected value can be infinite, even if the random variable is finite-valued.
• ### Can the value of an objective function be negative?

Objective function coefficients. The cost/profit coefficients (typically referred to as cj) are entered as numerical values. These coefficients may be positive or negative.
• ### What is also defined as the non-negative variable?

iii) Artificial variables are also defined as the non-negative variables. which are added in the LHS of the constraints to convert equality into the standard form of simplex.
• ### Can a constraint be negative?

These are called constraints. The variables must also satisfy the non-negativity condition: they can’t be negative. The set of points, or values of the variables, which satisfy the con- straints and the non-negativity condition is called the feasible set.
• ### Is zero a non-negative number?

Signed numbers

Because zero is neither positive nor negative, the term nonnegative is sometimes used to refer to a number that is either positive or zero, while nonpositive is used to refer to a number that is either negative or zero. Zero is a neutral number.

• ### Which of the following are non-negative?

Since zero is neither positive nor negative .

Explore Can expectation value be negative? with tags: Can expectation value be negative in quantum mechanics, Can variance be negative, Can x be negative in a probability distribution, the expected value of a binomial random variable can not be negative., A random variable can be discrete or continuous, Expected value

## Excellent information on Can expectation value be negative?

### Why does expectation values are always nonnegative?

• Summary: Why does expectation values are always nonnegative? Why does the expectation values of some operators, such as ‘number’ operator ##a^\dagger a## and atomic population operator ##\sigma^\dagger\sigma##, are always nonnegative? Can we prove this from a mathematical point? For example, are these operators positive semidefinite? Last edited: Apr 6, 2015 Answers and Replies Why does the expectation values of some operators, such as ‘number’ operator $a^{\dag}a$ and atomic population operator…
• Rating: 2.86 ⭐

### Can the expectation value of the square of momentum be …

• Summary: Can the expectation value of the square of momentum be negative? $\begingroup$ I’ve been solving a problem in quantum mechanics, and I was deriving the standard deviation of $P$, knowing that $\langle P\rangle=0$. Because $\Delta P=\sqrt{\langle P^2 \rangle – \langle P \rangle ^2} = \sqrt{\langle P^2 \rangle}$, I was trying to calculate the expectation value of the square of the momentum. The wave function was given by $\psi(x)=\sqrt{\alpha}e^{-\alpha|x|}$ where…
• Rating: 2.88 ⭐
• Source: https://physics.stackexchange.com/questions/104335/can-the-expectation-value-of-the-square-of-momentum-be-negative

### Can the expectation of a continuous random variable be …

• Summary: Can the expectation of a continuous random variable be negative? 1 Answer Sorted by: Reset to default 1 $\begingroup$ Consider a random variable $X$, with expectation $1$. Now $Y:=X-2$ is also a random variable and has expectation $-1$. Of course, the expectation of a non-negative random variable cannot be negative. answered Apr 17, 2020 at 6:49 user65203user65203 $\endgroup$ Add a comment  |  Your Answer Sign up…
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• Source: https://math.stackexchange.com/questions/3629562/can-the-expectation-of-a-continuous-random-variable-be-negative

### What is Expected Value? – Towards Data Science

• Summary: What is Expected Value? – Towards Data ScienceAn intuitive explanation of expected value with simple examples using gamesExpected value is the average value of a random variable over a large number of experiments. A random variable maps numeric values to each possible outcome in an experiment. We can calculate expected value for a discrete random variable — one in which the number of potential outcomes is…
• Rating: 1.83 ⭐
• Source: https://towardsdatascience.com/what-is-expected-value-4815bdbd84de

### Expected value – Wikipedia

• Summary: Expected value This article is about the term used in probability theory and statistics. For other uses, see Expected value (disambiguation). “E(X)” redirects here. For the function, see Exponential function. In probability theory, the expected value (also called expectation, expectancy, mathematical expectation, mean, average, or first moment) is a generalization of the weighted average. Informally, the expected value is the arithmetic mean…
• Rating: 4.78 ⭐
• Source: https://en.wikipedia.org/wiki/Expected_value

### Can expectation value be negative? – FAQ Blog

• Summary: Can expectation value be negative? Explained by FAQ Blog Last Update: May 30, 2022This is a question our experts keep getting from time to time. Now, we have got the complete detailed explanation and answer for everyone, who is interested! Asked by: Alphonso Franecki Score: 4.6/5 (25 votes) The expectation value of the square of the momentum operator cannot be negative. Can expectations be negative? Expected value…
• Rating: 3.83 ⭐
• Source: https://faq-blog.com/can-expectation-value-be-negative

### Expected Value – Definition and examples – Conceptually

• Summary: Expected Value – Definition and examples — ConceptuallyWhat is expected value?Definition and explanationExpected value is the probability multiplied by the value of each outcome. For example, a 50% chance of winning $100 is worth$50 to you (if you don’t mind the risk). We can use this framework to work out if you should play the lottery. Let’s say a ticket costs \$10, and you have a 0.0000001 chance…
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• Source: https://conceptually.org/concepts/expected-value

### What does the expectation value *really* represent … – Postulate

• Summary: What does the expectation value *really* represent? [Unanswered question] | PostulateWhen building a QGAN following the Pennylane tutorial, I came across something strange: the expectation value that the circuit returns with the function qml.expval() is not equal to the probability of the discriminator classifying the data as real. This sounded like saying, the expectation value of, for example, a qubit that can collapse into either |0⟩ or |1⟩ upon…
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• Source: https://postulate.us/@laura/p/2021-04-04-What-does-the-expectation-value-dLN9Q22QWVWNWGu8FAvQ1h

### 4.4 Expectation Value and Standard Deviation

• Summary: 4.4 Expectation Value and Standard Deviation  Quan­tum Me­chan­ics for En­gi­neers   © Leon van Dom­me­len  Sub­sec­tions 4.4.1 Sta­tis­tics of a die 4.4.2 Sta­tis­tics of quan­tum op­er­a­tors 4.4.3 Sim­pli­fied ex­pres­sions 4.4.4 Some ex­am­ples 4.4 Ex­pec­ta­tion Value and Stan­dard De­vi­a­tion It is a strik­ing con­se­quence of quan­tum me­chan­ics that phys­i­cal quan­ti­ties may not have a value. This oc­curs when­ever the wave func­tion is not an eigen­func­tion of the quan­tity of…
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• Source: https://eng-web1.eng.famu.fsu.edu/~dommelen/quantum/style_a/esd.html

### 7.2 Time Variation of Expectation Values

• Summary: 7.2 Time Variation of Expectation Values  Quan­tum Me­chan­ics for En­gi­neers   © Leon van Dom­me­len  Sub­sec­tions 7.2.1 New­ton­ian mo­tion 7.2.2 En­ergy-time un­cer­tainty re­la­tion 7.2 Time Vari­a­tion of Ex­pec­ta­tion Val­ues The time evo­lu­tion of sys­tems may be found us­ing the Schrö­din­ger equa­tion as de­scribed in the pre­vi­ous sec­tion. How­ever, that re­quires the en­ergy eigen­func­tions to be found. That might not be easy. For some sys­tems, es­pe­cially…
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• Source: https://eng-web1.eng.famu.fsu.edu/~dommelen/quantum/style_a/schrodc.html

### Lesson 23 Expected Value and Infinity

• Summary: Lesson 23 Expected Value and Infinity | Introduction to Probability Pascal’s Wager The mathematician Blaise Pascal (1623-1662) made an argument for why it was rational to believe in God—at least the Judeo-Christian God. Pascal acknowledged that God may or may not exist and assigned the probability $$p > 0$$ to God’s existence. Then, he considered the following bets: If you believe in God,…
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• Source: https://dlsun.github.io/probability/ev-infinity.html