Probability

Question 1

In the context of probability, what is the Sample Space?

Answer 1

The sample space S of a random phenomenon is the set of all possible outcomes.

Question 2

In the context of probability, what is an Event?

Answer 2

An event is an outcome or a set of outcomes of a random phenomenon. That is, an event is a subset of the sample space.

Question 3

In the context of probability, what is a Probability Model?

Answer 3

A mathematical description of a random phenomenon consisting of two parts: a sample space S and a way of assigning probabilities to events.

Question 4

What are the four Probability Rules?

Answer 4

1. Any probability is a number between 0 and 1
2. All possible outcomes together must have probability 1
3. If two events have no outcomes in common, the probability that one or the other occurs is the sum of their individual probabilities.
4. The probability that an event does not occur is 1 minus the probability that the event does occur.

Question 5

In terms of probability, what is a true Random Variable?

Answer 5

A variable whose value is a numerical outcome of a random phenomenon.

Question 6

What is the Probability Distribution of a variable?

Answer 6

The probability distribution of a random variable x tells us what values x can take and how to assign probabilities to those values.