What you’ll learn
Understand probabilities from 0 to 1.
Key idea
Probability 0 is impossible and 1 is certain; intermediate values describe likelihood, not a guaranteed next outcome.
Only model probability1is certain and0impossible; intermediate chances do not guarantee an individual result.
Worked example
Enter the exact value or ordered values in the format requested below.
A probability line from 0 to 1 has 5 equal intervals. Event E is marked 3 intervals to the right of 0. Enter its exact probability.
- Each equal interval on the 0-to-1 line is 1/5; marker 3 is at 3/5=3/5.
- Under the supplied probability model this means more likely than not; only probability 1 guarantees the event.
Answer: 3/5
Quick Check
Interpret the result of 'Understand probabilities from 0 to 1' in the data-generating context, including units and population limits.
Model event E has probability 7/8, represented by marker 7 on a 0-to-1 line with 8 equal intervals. Interpret its likelihood rather than assuming every next trial succeeds.