The Probability Scale
Probability - by Ray Nanji
Probability is a chance of an event occuring
the extent to which an event is likely to occur, measured by the ratio of the favourable cases to the whole number of cases possible
the extent to which something is likely to happen or be the case
Keywords in Probability
CHANCE - a possibility of something happening.
Event - a thing that happens or takes place, especially one of importance.
RANDOM - made, done, or happening without method or conscious decision.
PREDICTABLE - An expected result
Sample Space - he sample space of an experiment or random trial is the set of all possible outcomes or results of that experiment.
Bias - Bias, prejudice mean a strong inclination of the mind or a preconceived opinion about something or someone. A bias may be favorable or unfavorable: bias in favor of or against an idea.
Outcome - an outcome is a possible result of an experiment or trial. Each possible outcome of a particular experiment is unique, and different outcomes are mutually exclusive. All of the possible outcomes of an experiment form the elements of a sample space
The probability vocabulary and scale
Probabilities go from 0 to 1 as decimals and fractions or from 0% to 100%
A probability of 1 or 100 % is described as CERTAIN
A probability of 0 is said to be IMPOSSIBLE
A probability of 50 % or 1/2 or 0.5 is described as being EVEN
A probability of between 0 and 0.5 or 0 and 1/2 or 0 % and 50 % is described as being UNLIKELY
A probability between 0.5 and 1or 1/2 and 1 or 50 % and 100 % is described as being LIKELY
Types of Probabilities
Experimental Probability or relative frequency - Experimental probability is probability that is determined on the basis of the results of an experiment repeated many times
Theoretical Proability - Theoretical probability is probability that is determined on the basis of reasoning.
A die is rolled once. What is the probability of rolling a 5? Your answer should be a fraction in simplest form.
Probability can be written as ...
A likely chance event is closer to what number?
A bag contains 5 quarters, 2 dimes, and 4 pennies. What is the probability of picking a quarter?