Chapter 5: A Survey of Probability Concepts

How do you calculate classical probability?

The number of favorable outcomes divided by the number of possible outcomes.

Which of the following numbers could represent a probability that an event will occur? Select all that apply. 110% 25% -0.3 0.43 5/4 3/4 1.2

25% 0.43 3/4

If the fraction of times an even happened in the past is used for the basis for assigning a probability to an event, this is_______ Probability. Classical Subjective Empirical

Empirical

Which of the following statements describe a probability? Select all that apply. It describes the relative likelihood that an even will occur. It is always expressed as a percentage. It is a number between 0 and 1, inclusive. A probability that lies between minus 1 and plus 1.

It describes the relative likelihood that an even will occur. It is a number between 0 and 1, inclusive.

What is the propose of using selection WITH replacement?

The probabilities do not change from one trial to another, so the events are independent.

The event ~A

is the complement of event A.

Two events are independent if:

the occurrence of one event does not affect the likelihood that the other will occur.

The special rule of addition describes how to calculate which of the following probabilities? P(A/B) P(A or B) P(A and B)

P(A or B)

What is an assumption upon which classical probability is based?

That the outcomes of an experiment are equally likely.

How would you read the formula for P(~A)?

The Probability of not A.

Conditional probability example:

The chance an employee will do well on the job given the employee scored well on a per-employment test.

Which one of the following is true about the events that are both mutually exclusive and collectively exhaustive? The sum of their probabilities must be between 0 and 1. The sum of their probabilities must be 0. The sum of their probabilities must be 1. The sum of their probabilities must be greater than 1.

The sum of their probabilities must be 1.

Select the methodology that would result in a subjective probability. Dividing the number of favorable events by the number of possible events. Studying the fraction of times in the past a particular event has happened. Weighing the available information and assigning a probability.

Weighing the available information and assigning a probability.

As the number of trials increase, what does the law of large numbers say about the probabilities? The classical probability will approach the true probability. The subjective probability will approach the true probability. The empirical probability will approach the event's true probability.

The empirical probability will approach the event's true probability.

What does it mean when an experiment has a set of events that are collectively exhaustive? That at least one of the events must occur. That all of the events will occur. That only one of the events can occur as a result of the experiment.

That at least one of the events must occur.

Which of the following best describes the meaning of "Outcome" in the context of probability experiment? All the possible results of the experiment. A collection of 2 or more results of the experiment. A particular result of the experiment.

A particular result of the experiment.

Which of the following is the best definition of "Event"in the context of probability experiment? A set of 1 or more outcomes of an experiment. A particular outcome of a random experiment. The process of performing a random experiment.

A set of 1 or more outcomes of an experiment.

The value given for an empirical probability is based on: the past history of outcomes from the experiment. the ratio of favorable outcomes to possible outcomes to the experiment. someone's "best guess" on this knowledge of this situation.

the past history of outcomes from the experiment.

Choose the statement that best defines the term " Experiment" in the context of probability. A process that lead to only one of several possible outcomes. A process that may or may not confirm a hypothesis. A test conducted by scientists in a laboratory.

A process that lead to only one of several possible outcomes.