Question

when two or more events can occur concurrently it is called
a. a tree diagram.
b. joint probability.
c. empirical probability.
d. conditional probability.

Explanation:

• A tree diagram is a visual tool for mapping event sequences, not concurrent events.
• Empirical probability is based on observed data frequencies.
• Conditional probability focuses on events dependent on prior outcomes.
• Joint probability describes the likelihood of two or more events happening at the same time, matching the question's definition.

Answer:

b. joint probability.