Which probability distribution assigns equal probability to each of a finite number of outcomes?

Which probability distribution assigns equal probability to each of a finite number of outcomes?

• A. Discrete uniform probability distribution
• B. Normal distribution
• C. Binomial distribution
• D. Exponential distribution

Answer: (A)

This question tests the idea of a discrete uniform distribution, where a finite set of outcomes is each equally likely. In this kind of distribution, every outcome has the same probability, namely 1 over the number of outcomes. For example, a fair six-sided die has six possible results, and each result has probability 1/6, so the probabilities across all outcomes sum to 1. This differs from other common distributions. The normal distribution involves a continuous range of values, not a finite list, so the probability of any exact value is effectively zero and probabilities are described by areas under the bell-shaped curve. The binomial distribution assigns probabilities to the number of successes across several trials, and those probabilities vary with the count unless in a degenerate, nonsensical case. The exponential distribution is also continuous with a decreasing density over [0, ∞), so outcomes aren’t equally likely. So the distribution that assigns equal probability to each of a finite number of outcomes is the discrete uniform distribution.

This question tests the idea of a discrete uniform distribution, where a finite set of outcomes is each equally likely. In this kind of distribution, every outcome has the same probability, namely 1 over the number of outcomes. For example, a fair six-sided die has six possible results, and each result has probability 1/6, so the probabilities across all outcomes sum to 1.

This differs from other common distributions. The normal distribution involves a continuous range of values, not a finite list, so the probability of any exact value is effectively zero and probabilities are described by areas under the bell-shaped curve. The binomial distribution assigns probabilities to the number of successes across several trials, and those probabilities vary with the count unless in a degenerate, nonsensical case. The exponential distribution is also continuous with a decreasing density over [0, ∞), so outcomes aren’t equally likely.

So the distribution that assigns equal probability to each of a finite number of outcomes is the discrete uniform distribution.