Math Problem Statement

Can you help me solve this equation

Can you help me solve this equation

Solution

Certainly, let’s solve this step by step.

The table provides the values of a random variable XX along with their associated probabilities P(x)P(x). The goal is to find the expected value E(4X+Δ)E(-4X + \Delta), where Δ\Delta is a constant.

Step 1: Calculate E(X)E(X)

The expectation E(X)E(X) is calculated as follows: E(X)=ixiP(xi)E(X) = \sum_{i} x_i P(x_i) where xix_i are the values that XX can take, and P(xi)P(x_i) are the probabilities.

From the table:

  • x=0x = 0 with P(x)=0.25P(x) = 0.25
  • x=1x = 1 with P(x)=0.21P(x) = 0.21
  • x=2x = 2 with P(x)=0.15P(x) = 0.15
  • x=3x = 3 with P(x)=0.14P(x) = 0.14

Calculating E(X)E(X): E(X)=(0×0.25)+(1×0.21)+(2×0.15)+(3×0.14)E(X) = (0 \times 0.25) + (1 \times 0.21) + (2 \times 0.15) + (3 \times 0.14) E(X)=0+0.21+0.30+0.42=0.93E(X) = 0 + 0.21 + 0.30 + 0.42 = 0.93

Step 2: Calculate E(4X+Δ)E(-4X + \Delta)

Using the linearity of expectation, we can separate the expectation: E(4X+Δ)=4E(X)+E(Δ)E(-4X + \Delta) = -4E(X) + E(\Delta) Since Δ\Delta is a constant, E(Δ)=ΔE(\Delta) = \Delta.

Thus, E(4X+Δ)=40.93+ΔE(-4X + \Delta) = -4 \cdot 0.93 + \Delta E(4X+Δ)=3.72+ΔE(-4X + \Delta) = -3.72 + \Delta

Final Answer

The expected value E(4X+Δ)=3.72+ΔE(-4X + \Delta) = -3.72 + \Delta.

Would you like further clarification on any step or additional details?

Here are some related questions that might interest you:

  1. What if the constant Δ\Delta was specified? How would that affect the expectation?
  2. How would you calculate E(X2)E(X^2) using the same table of values?
  3. Can you determine the variance Var(X)\text{Var}(X) with the given information?
  4. How would E(aX+b)E(aX + b) change for arbitrary constants aa and bb?
  5. What if the probabilities were adjusted? How would that impact E(X)E(X)?

Tip: Always remember that constants factor out in expectations, simplifying calculations greatly!

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Math Problem Analysis

Mathematical Concepts

Probability
Expected Value
Linear Transformation

Formulas

E(X) = Σ x_i * P(x_i)
E(aX + b) = aE(X) + b

Theorems

Linearity of Expectation

Suitable Grade Level

Grades 11-12