3.1 Basic Concepts of Probability

Question 1

Probability Experiment

Answer 1

An action or trial through which specific results are obtained.

Question 2

Simple Probability

Answer 2

of successful outcomes / total number of outcomes

Question 3

Impossible Event

Answer 3

0 probability of occurring

Question 4

Certain Event

Answer 4

Probability of 1

Question 5

Unlikely Event

Answer 5

Probability between 0 and 0.50

Question 6

Likely Event

Answer 6

Probability between 0.50 and 1

Question 7

Unusual Event

Answer 7

Probability less than 0.05

Question 8

Usual Event

Answer 8

Probability more than 0.05

Question 9

Sample Space

Answer 9

Set of all outcomes of a probability experiment

Question 10

Theoretical (classical) Probability

Answer 10

Used when each outcome in a sample space is equally likely to occur.
- Probability of drawing a card from a standard deck.

Question 11

Experimental (empirical) probability

Answer 11

Based on observations obtained from probability experiments.
- outcomes from actually rolling a number cube or flipping a coin (usually don’t match theoretical probability)

Question 12

Subjective Probability

Answer 12

Results from intuition, educated guesses, and estimates.
- Probability of recovery made by a doctor’s wealth

Question 13

Complement of event E

Answer 13

Set of all outcomes in a sample space that are not included in event E; denoted as E prime (E’)
- sum of probability and complement equals one

Question 14

Law of Large Numbers

Answer 14

As an experiment is repeated over and over, the empirical probability of an event appears to be the theoretical probability of the event.

Question 15

Odds in Favor (odds of winning)

Answer 15

Ration of success to unsuccessful

Question 16

Odds against

Answer 16

Ratio of unsuccessful