Probability distribution is:

Probability distribution is:

• A. A curve describing an idealized frequency distribution from which the probability of specific values can be determined; for categorical variables it's a formula yielding category probabilities.
• B. A single probability value.
• C. The distribution of categories for a qualitative variable.
• D. The evidence used in model selection.

Answer: (A)

A probability distribution tells you how likely each possible value of a variable is. For continuous variables, this is often shown as a curve (a density function) where the area under the curve over an interval equals the probability of outcomes within that interval. For categorical (qualitative) variables, the distribution is given by the probabilities associated with each category, typically shown as a formula or table that sums to 1. This description captures both the idea of probabilities across all possible outcomes and how they are represented, whether as a curve for continuous data or as category probabilities for discrete, categorical data. The other options are too narrow: a single probability value isn't a full distribution, describing only qualitative categories omits the broader concept of probabilities across all outcomes, and the evidence used in model selection is a different concept entirely.

A probability distribution tells you how likely each possible value of a variable is. For continuous variables, this is often shown as a curve (a density function) where the area under the curve over an interval equals the probability of outcomes within that interval. For categorical (qualitative) variables, the distribution is given by the probabilities associated with each category, typically shown as a formula or table that sums to 1. This description captures both the idea of probabilities across all possible outcomes and how they are represented, whether as a curve for continuous data or as category probabilities for discrete, categorical data. The other options are too narrow: a single probability value isn't a full distribution, describing only qualitative categories omits the broader concept of probabilities across all outcomes, and the evidence used in model selection is a different concept entirely.