Math Problem Statement

Find the expected value E(X) of the following data. Round your answer to one decimal place.

x 2 3 4 5 6 P(X=x) 0.3 0.1 0.2 0.1 0.3

Solution

To find the expected value E(X)E(X) of a random variable XX, we use the formula:

E(X)=(xP(X=x))E(X) = \sum (x \cdot P(X = x))

Given the dataTo find the expected value E(X)E(X) of a random variable XX, we use the formula:

E(X)=(xP(X=x))E(X) = \sum (x \cdot P(X = x))

Given the

  • x=2,3,4,5,6x = 2, 3, 4, 5, 6
  • P(X=x)=0.3,0.1,0.2,0.1,0.3P(X = x) = 0.3, 0.1, 0.2, 0.1, 0.3

We compute the expected value as follows:

E(X)=(20.3)+(30.1)+(40.2)+(50.1)+(60.3)E(X) = (2 \cdot 0.3) + (3 \cdot 0.1) + (4 \cdot 0.2) + (5 \cdot 0.1) + (6 \cdot 0.3)

Calculating each term:

E(X)=2(0.3)+3(0.1)+4(0.2)+5(0.1)+6(0.3)E(X) = 2(0.3) + 3(0.1) + 4(0.2) + 5(0.1) + 6(0.3) E(X)=0.6+0.3+0.8+0.5+1.8E(X) = 0.6 + 0.3 + 0.8 + 0.5 + 1.8 E(X)=4.0E(X) = 4.0

So, the expected value E(X)E(X) is 4.0.

Would you like more details or have any further questions?

Here are 5 related questions:

  1. How is the concept of expected value used in decision-making?
  2. How does changing the probabilities affect the expected value?
  3. What is the significance of expected value in probability theory?
  4. How would you calculate the variance of XX based on this data?
  5. How does the expected value differ for continuous vs. discrete random variables?

Tip: The expected value gives a long-run average of outcomes weighted by their probabilities.

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Math Problem Analysis

Mathematical Concepts

Probability
Expected Value

Formulas

E(X) = ∑(x * P(X = x))

Theorems

Law of Total Expectation

Suitable Grade Level

Grades 9-12