Final answer:
The probability that a person must wait at least 1.5 more hours is 0.4.
Step-by-step explanation:
A tree diagram is a graphical representation that displays the hierarchical structure of a set of interconnected elements. It is often used to depict the outcomes of a series of events or decisions in a systematic way. Tree diagrams are particularly useful in probability theory, decision analysis, and problem-solving to visualize different paths and outcomes.
Tree Diagram
Here is a tree diagram for the given problem:
Answer to part a:
The probability that a person must wait at least 1.5 more hours is 0.4. This means that there is a 40% chance that a person will have to wait for 1.5 or more hours past noon on a delivery day.