Math Problem Statement

From the figure, what is the probability that a randomly selected X is between 0.7 and 1.66?

Solution

This problem involves a uniform distribution of a random variable XX over the interval [0,2][0, 2].

Key Information:

  1. The random variable XX is uniformly distributed over [0,2][0, 2], meaning the probability density function (PDF) is constant on this interval.
  2. The total probability over the entire interval [0,2][0, 2] is 1, so the height of the PDF is given by: f(x)=1length of the interval=12f(x) = \frac{1}{\text{length of the interval}} = \frac{1}{2}

Problem Statement:

We are asked to find the probability that XX falls between 0.7 and 1.66.

For a uniform distribution, the probability of XX being between two values aa and bb is the length of that interval (ba)(b - a) multiplied by the height of the PDF f(x)f(x): P(aXb)=(ba)×f(x)P(a \leq X \leq b) = (b - a) \times f(x)

Solution:

  1. The length of the interval between 0.7 and 1.66 is: 1.660.7=0.961.66 - 0.7 = 0.96
  2. The height of the PDF is f(x)=12f(x) = \frac{1}{2}.

Thus, the probability is: P(0.7X1.66)=0.96×12=0.48P(0.7 \leq X \leq 1.66) = 0.96 \times \frac{1}{2} = 0.48

Therefore, the probability that a randomly selected XX is between 0.7 and 1.66 is 0.48.

Would you like any further clarification or details on this? Here are some related questions you might find useful:

  1. How do you calculate the probability for a uniform distribution over a different interval?
  2. What is the significance of the area under the probability density function (PDF)?
  3. How would this problem change if the distribution were not uniform?
  4. What is the cumulative distribution function (CDF) for a uniform distribution?
  5. How does the probability change if the interval of XX is expanded?

Tip: For uniform distributions, the probability is proportional to the length of the interval, making it simple to compute as the area of a rectangle.

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Math Problem Analysis

Mathematical Concepts

Probability
Uniform Distribution

Formulas

P(a ≤ X ≤ b) = (b - a) * f(x)
f(x) = 1 / (b - a) for a uniform distribution

Theorems

Uniform Distribution Theorem

Suitable Grade Level

Grades 11-12 or early college level