What is the formula for expected value 2024?

Harper Wilson | 2023-06-17 06:39:50 | page views:1291
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Charlotte Wilson

Studied at Cambridge University, Lives in Cambridge, UK
Hello there, I'm an expert in the field of statistics and probability theory. It's a pleasure to help you understand the concept of expected value.

Expected value is a fundamental concept in probability theory and statistics, and it represents the average outcome of a random event if it were to be repeated a large number of times. It's a measure of the central tendency of a probability distribution and is often used to make decisions under uncertainty.

The formula for the expected value, often denoted as \( E(X) \) or \( \mu \), is calculated by multiplying each possible outcome of a random variable \( X \) by its probability of occurrence and then summing these products. For a discrete random variable, the formula is:

\[
E(X) = \sum_{i=1}^{n} x_i \cdot P(x_i)
\]

Where:
- \( E(X) \) is the expected value of the random variable \( X \).
- \( x_i \) represents each possible outcome of the random variable \( X \).
- \( P(x_i) \) is the probability of the outcome \( x_i \) occurring.
- \( n \) is the total number of possible outcomes.

The expected value can also be thought of as the long-term average of the outcomes. For example, if you were to flip a fair coin repeatedly, the expected number of heads would be 0.5, because over a large number of flips, you would expect to get heads about half the time.

Now, let's address the formula you've mentioned: (P(x) * n). This seems to be a simplified version or a misinterpretation of the expected value formula. The correct formula does not multiply the probability by the number of times an event happens but rather by the value of each outcome and sums these products. The number of times an event happens is not directly a part of the formula for expected value.

The expected value is particularly useful in various fields such as finance, economics, and decision theory, where it helps in evaluating the potential return on an investment or the average outcome of a decision.

It's also important to note that the expected value can be used for continuous random variables as well. In that case, the summation becomes an integral, and the formula is:

\[
E(X) = \int_{-\infty}^{\infty} x \cdot f(x) \, dx
\]

Where:
- \( f(x) \) is the probability density function of the continuous random variable \( X \).

In summary, the expected value is a powerful tool in probability and statistics that helps us understand the average outcome of a random variable. It's calculated by multiplying each outcome by its probability and summing these products, which gives us a single value that represents the central tendency of the distribution.


2024-06-16 10:08:09

Lucas Patel

Works at the International Development Association, Lives in Washington, D.C., USA.
The basic expected value formula is the probability of an event multiplied by the amount of times the event happens: (P(x) * n). The formula changes slightly according to what kinds of events are happening.Oct 28, 2017
2023-06-22 06:39:50

Mia Thompson

QuesHub.com delivers expert answers and knowledge to you.
The basic expected value formula is the probability of an event multiplied by the amount of times the event happens: (P(x) * n). The formula changes slightly according to what kinds of events are happening.Oct 28, 2017
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