Math Problem Statement

Let the probability distribution of X be given by X 0 1 2 3 4 . P(X=x) K 2K 3K 5K 2K .i) Find the value of K .ii) Find P(x≥2), P(x<2), P(x≤3)

Solution

Given the probability distribution of XX as follows:

X:01234X: \quad 0 \quad 1 \quad 2 \quad 3 \quad 4 P(X=x):K2K3K5K2KP(X = x): \quad K \quad 2K \quad 3K \quad 5K \quad 2K

i) Finding the value of KK:

The sum of all probabilities for a discrete random variable must equal 1:

K+2K+3K+5K+2K=1K + 2K + 3K + 5K + 2K = 1

Simplifying this:

K(1+2+3+5+2)=1K(1 + 2 + 3 + 5 + 2) = 1

K(13)=1K(13) = 1

K=113K = \frac{1}{13}

ii) Finding the probabilities:

  1. P(X2)P(X \geq 2): This includes X=2X = 2, X=3X = 3, and X=4X = 4.

P(X2)=P(X=2)+P(X=3)+P(X=4)P(X \geq 2) = P(X = 2) + P(X = 3) + P(X = 4)

P(X2)=3K+5K+2K=10K=10×113=1013P(X \geq 2) = 3K + 5K + 2K = 10K = 10 \times \frac{1}{13} = \frac{10}{13}

  1. P(X<2)P(X < 2): This includes X=0X = 0 and X=1X = 1.

P(X<2)=P(X=0)+P(X=1)P(X < 2) = P(X = 0) + P(X = 1)

P(X<2)=K+2K=3K=3×113=313P(X < 2) = K + 2K = 3K = 3 \times \frac{1}{13} = \frac{3}{13}

  1. P(X3)P(X \leq 3): This includes X=0X = 0, X=1X = 1, X=2X = 2, and X=3X = 3.

P(X3)=P(X=0)+P(X=1)+P(X=2)+P(X=3)P(X \leq 3) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3)

P(X3)=K+2K+3K+5K=11K=11×113=1113P(X \leq 3) = K + 2K + 3K + 5K = 11K = 11 \times \frac{1}{13} = \frac{11}{13}

Summary:

  1. K=113K = \frac{1}{13}
  2. P(X2)=1013P(X \geq 2) = \frac{10}{13}
  3. P(X<2)=313P(X < 2) = \frac{3}{13}
  4. P(X3)=1113P(X \leq 3) = \frac{11}{13}

Would you like a more detailed explanation or have any questions?

Here are 5 related questions:

  1. How would the probability distribution change if P(X=3)P(X = 3) was doubled?
  2. What is the expected value E(X)E(X) for this distribution?
  3. How do you calculate the variance of this probability distribution?
  4. If another value X=5X = 5 is added with probability KK, how would KK change?
  5. What is the cumulative distribution function (CDF) for this random variable XX?

Tip: When dealing with probability distributions, always check that the total probability sums to 1 before making any calculations.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Probability Theory
Discrete Random Variables
Probability Distribution

Formulas

Sum of probabilities in a discrete distribution

Theorems

-

Suitable Grade Level

High School