Practice For Discrete Random Variables (14.2.1) - Joint Probability Distributions

Practice: For Discrete Random Variables

Lesson 14.2.1Joint Probability Distributions

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10 questions

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6 sample questions

Question 1.
What does the joint pmf for two discrete random variables provide?
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Consider what 'joint' means in the context of probability.
Question 2.
Write the first property of joint probability distributions.
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Think about what probabilities should always be.
3Question 3.
What does a joint probability mass function describe?
- The probability of one random variable
- The combined probability of two discrete random variables
- The area under a curve
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Focus on 'joint' – it's about combinations.
4Question 4.
True or False: A joint pmf must always yield a negative probability.
- True
- False
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Probabilities should not dip below zero!
Question 5.
Suppose you have a joint pmf with P(X=0, Y=1) = 0.3 and P(X=0, Y=2) = 0.2. Calculate the marginal pmf for P(X=0).
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Total all probabilities corresponding to X=0.
Question 6.
Given a joint pmf indicating the failure rate of two machines X and Y is connected, show if they are independent or not, and explain why.
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Independence means multiplication of individual probabilities works every time!

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