Math Problem Statement

From this density, the probability that X is at least 0.2 is:

Solution

The image shows a probability density function (PDF) for a random variable XX over the interval [0,2][0, 2]. The PDF appears to be a uniform distribution, as the height of the function is constant between 00 and 22, with a height of 0.50.5. This suggests a piecewise uniform distribution.

We need to compute the probability that XX is at least 0.2, i.e., P(X0.2)P(X \geq 0.2).

Step-by-Step Solution:

  1. Recognize the total probability: The total probability for the PDF must integrate to 1. Since the function is constant between 0 and 2, the height of the PDF is 12\frac{1}{2} (because the area under the curve must be 1, and the length of the interval is 2).

  2. Set up the integral: The probability that X0.2X \geq 0.2 is the area under the curve from 0.20.2 to 22, which can be found by integrating the PDF: P(X0.2)=0.220.5dxP(X \geq 0.2) = \int_{0.2}^{2} 0.5 \, dx

  3. Evaluate the integral: P(X0.2)=0.5×(20.2)=0.5×1.8=0.9P(X \geq 0.2) = 0.5 \times (2 - 0.2) = 0.5 \times 1.8 = 0.9

Thus, the probability that X0.2X \geq 0.2 is 0.9.

Let me know if you need further clarification or details!

Here are some follow-up questions to extend this understanding:

  1. What is the probability that XX is less than or equal to 1?
  2. What is the probability that XX lies between 0.5 and 1.5?
  3. How would the PDF change if the total range was from 0 to 3 instead of 0 to 2?
  4. What if the height of the PDF was different, say 0.25? How would the probabilities change?
  5. How do you compute the expected value of XX for this uniform distribution?

Tip:

For uniform distributions, probabilities are directly proportional to the lengths of intervals within the range, making integrals simple to compute!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Probability
Probability Density Function (PDF)
Integration

Formulas

P(X ≥ 0.2) = ∫ from 0.2 to 2 of 0.5 dx

Theorems

Total Probability Theorem
Basic Integration Theorem

Suitable Grade Level

Grades 11-12