Extent to which 2 factors vary together—can be used to predict the probability that one event will occur.

• A. Correlation
• B. Data
• C. Frequency/Count
• D. Contingency

Answer: (A)

Correlation is the extent to which two factors vary together and thus can be used to predict the probability that one event will occur based on information about the other. When the two variables move together in the same direction, that’s a positive correlation; when one tends to rise as the other falls, that’s a negative correlation. The stronger this relationship, the more reliably you can infer the likelihood of one event from the value of the other. This idea goes beyond just collecting data or counting occurrences, because it captures how two things co-vary and informs predictive relationships. It’s distinct from a simple contingency or from raw data alone, which don’t by themselves describe the degree of association between two variables.