Which of the following is a valid probability distribution for a discrete random variable? Check all that apply.
A. 0.18, 0.12, 0.03, 0.08, 0.21, 0.04, 0.05, 0.16, 0.25, 0.21, 0.17
B. 0.02, 0.03, 0.21, 0.16, 0.04, 0.12, 0.18, 0.05, 0.16, 0.03
C. 0.2, 0.2, 0.2, 0.2, 0.2
D. 0.1, -0.2, 0.1, -0.2 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1
E. 1.0
Answer:
For a valid probability distribution of a discrete random variable following two conditions must be met:
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Each probability P(x) must be between 0 and 1
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The sum of probabilities is 1, ∑P(x)=1
These two conditions are met by distributions b),c),e).
Sum of probabilities in a) is 1.5, so second condition is not met.
In d), there are some negative probabilities, so first condition is not met.