Math Problem Statement

Suppose that the random variable X** assumes three values 0, 1 and 2 with probabilities 1/3​, 1/6​ and 1/2​ respectively. Calculate the value of F(1)

Solution

To calculate the value of the cumulative distribution function (CDF) F(x)F(x) at x=1x = 1 for a discrete random variable XX, we need to find:

F(1)=P(X1)F(1) = P(X \leq 1)

Given the random variable XX assumes three values: 0,1,0, 1, and 22 with the following probabilities:

  • P(X=0)=13P(X = 0) = \frac{1}{3}
  • P(X=1)=16P(X = 1) = \frac{1}{6}
  • P(X=2)=12P(X = 2) = \frac{1}{2}

Step-by-Step Solution

The cumulative distribution function F(x)F(x) at x=1x = 1 is defined as:

F(1)=P(X1)=P(X=0)+P(X=1)F(1) = P(X \leq 1) = P(X = 0) + P(X = 1)

Substitute the given probabilities:

F(1)=13+16F(1) = \frac{1}{3} + \frac{1}{6}

Now, let's find a common denominator to add these fractions:

F(1)=26+16=36=12F(1) = \frac{2}{6} + \frac{1}{6} = \frac{3}{6} = \frac{1}{2}

Final Answer

The value of F(1)F(1) is 12\frac{1}{2}.

Would you like further details on this solution? Here are some related questions to explore:

  1. What is the value of F(2)F(2) for this random variable?
  2. How would you calculate F(x)F(x) for any xx not equal to 0, 1, or 2?
  3. What is the probability mass function (PMF) of XX?
  4. How would the CDF change if the probabilities were different?
  5. What does the CDF graph of this random variable look like?

Tip: The CDF F(x)F(x) for a discrete random variable is a step function that only increases at the points where the variable takes specific values.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Probability Theory
Cumulative Distribution Function (CDF)
Discrete Random Variables

Formulas

CDF definition: F(x) = P(X <= x)

Theorems

-

Suitable Grade Level

Grades 11-12