Q: Which formula is used to calculate the probability of an event $$A$$?

$$P(A) = \frac{\text{number of occurrences of A}}{\text{total number of outcomes}}$$

Question 1

Which of the following best describes the Rare Event Rule for Inferential Statistics?

Accepted Answer

If, under a given assumption, the probability of an observed event is extremely small, then the assumption is probably not correct.

Question 2

A simple event is defined as:

Accepted Answer

An event that cannot be broken down into simpler components.

Question 3

What is the sample space for flipping a coin and rolling a six-sided die?

Accepted Answer

12 outcomes

Question 4

Which of the following numbers cannot be a probability and why? $$15, 1.11, 0, 1, 0.3948, \sqrt{5}, 0.99, 0.0001, -0.2938$$

Accepted Answer

15, 1.11, \sqrt{5}, and -0.2938 because probabilities must be between 0 and 1, inclusive.

Question 5

If you flip three coins, how many possible outcomes are there in the sample space?

Accepted Answer

8

Question 6

A password consists of five capital letters, each used only once. How many different passwords can be formed?

Accepted Answer

$$\frac{26!}{21!}$$

Question 7

What is the probability of rolling a sum of 7 with two six-sided dice?

Accepted Answer

$$\frac{1}{6}$$

Question 8

Which of the following best describes classical probability?

Accepted Answer

Probability calculated when each event has an equal chance of occurring, without actually performing the experiment.

Question 9

If you have 4 shirts, 3 pairs of pants, and 3 pairs of shoes, how many different outfits can you make (one of each)?

Accepted Answer

36

Question 10

What is the value of $$5! ($$five factorial)?

Accepted Answer

120

Question 11

A door passcode uses four digits. The second digit must be four. The last digit must be even. How many passcodes are possible?

Accepted Answer

9000

Question 12

Which of the following statements about probability is FALSE?

Accepted Answer

Probabilities can be negative if the event is rare enough.

Question 13

You are purchasing a new car. There are 3 manufacturers, 2 car sizes, and 4 colors. How many different ways can you select one manufacturer, one car size, and one color?

Accepted Answer

24

Question 14

Which formula is used to calculate the probability of an event $$A$$?

Accepted Answer

$$P(A) = \frac{	ext{number of occurrences of A}}{	ext{total number of outcomes}}$$

Question 15

If you flip a coin, spin a spinner with 4 colors, and flip another coin, how many possible outcomes does the game have?

Accepted Answer

16

Question 16

Which of the following is an example of a dependent event?

Accepted Answer

Selecting a king from a deck, not replacing it, then selecting a queen.

Question 17

What is the main purpose of a tree diagram in probability?

Accepted Answer

To help find a sample space.

Question 18

Which of the following best describes relative frequency probability?

Accepted Answer

Probability calculated by recording data from a procedure that occurs.

Question 19

If the probability of an event is 0.25, what is the probability that the event does NOT occur?

Accepted Answer

0.75

Question 20

How many ways can you arrange 6 books on a shelf?

Accepted Answer

$$6!$$

Chapter 4: Probability – Introductory Statistics Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards