Question 1

Which of the following best describes a 'random phenomenon' as used in probability theory?

Accepted Answer

A situation in which we know what outcomes could happen, but not which particular outcome will happen on any given trial.

Question 2

If you flip a fair coin 4 times and get heads each time, what is the probability that the next flip will be tails?

Accepted Answer

$$0.5$$

Question 3

What is the Law of Large Numbers?

Accepted Answer

It states that the relative frequency of an event gets closer to the theoretical probability as the number of trials increases.

Question 4

Which of the following is NOT a requirement for a probability?

Accepted Answer

The probability of an event can be negative.

Question 5

Suppose you have one of each US paper currency: $$1, 2$$, $$5, 10$$, $$20, 50$$, $100. If 5 of these bills have a president's portrait, what is the probability of randomly selecting a bill with a president?

Accepted Answer

$$\frac{5}{7}$$

Question 6

If $$P(A) = 0.7$$, what is $$P(	ext{not } A)$$?

Accepted Answer

$$0.3$$

Question 7

Which of the following pairs of events are disjoint (mutually exclusive)?

Accepted Answer

Rolling a 5 or greater and rolling a 2 or less on a single die.

Question 8

If events $$A$$ and $$B$$ are independent and $$P(A) = 0.6$$, $$P(B) = 0.5$$, what is $$P(A 	ext{ and } B)$$?

Accepted Answer

$$0.3$$

Question 9

A certain airline has a probability of $$0.993 of $$not losing your luggage on a flight. What is the probability that your luggage is not lost on three independent flights?

Accepted Answer

$$0.993^3$$

Question 10

What is the probability that the airline loses your luggage on at least one of three independent flights, given the probability of not losing it on a single flight is $$0.993$$?

Accepted Answer

$$1 - 0.993^3$

Question 11

If the probability of contacting a household by phone is $$0.76$$, what is the probability of contacting both of the next two households (assuming independence)?

Accepted Answer

$$0.76 	imes 0.76$$

Question 12

Which of the following best describes 'personal probability'?

Accepted Answer

A subjective assessment of uncertainty not based on formal calculations.

Question 13

If you flip a fair coin 4 times, what is the probability of getting at least 3 heads?

Accepted Answer

$$\frac{5}{16}$$

Question 14

Which of the following statements about the Law of Large Numbers is TRUE?

Accepted Answer

It states that the relative frequency of an event approaches the theoretical probability as the number of trials increases.

Question 15

Which rule would you use to find the probability that at least one of several independent events occurs?

Accepted Answer

Complement Rule

Question 16

Suppose you roll a fair six-sided die. What is the probability of rolling a number greater than 4 or an even number?

Accepted Answer

$$\frac{4}{6}$$

Question 17

Which of the following pairs of events are NOT independent?

Accepted Answer

The temperature in Knoxville at noon on April 1st is 80 degrees or more, and snow is falling in Knoxville at noon on April 1st.

Question 18

If $$P(A) = 0.4$$ and $$P(B) = 0.3$$, and $$A$$ and $$B$$ are disjoint, what is $$P(A 	ext{ or } B)$$?

Accepted Answer

$$0.7$$

Question 19

Which of the following is a correct application of the Multiplication Rule?

Accepted Answer

Finding the probability of flipping two heads in a row with a fair coin.

Chapter 12: From Randomness to Probability – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards