Intro Probability and Odds

According to the Book of Odds website, the probability that a randomly selected U.S. adult usually eats breakfast is 0.61.  Why doesn't the probability say that if you ask 100 U.S. adults at random if they usually eat breakfast, exactly 61 of them will say yes?

• Because probability must be expressed as a decimal.

• Because "usually" is not a scientific way to measure.

• Because 100 randomly selected U.S. adults represent a sample, and results may vary from sample to sample.

• Because of response bias.

Probability is a measure of how likely an outcome is to occur.  Which of the following probability best matches the statement:  "This outcome is impossible.  It can never occur."

• 0

• 0.01

• 0.6

• 1

Probability is a measure of how likely an outcome is to occur.  Which of the following probability best matches the statement:  "This outcome is certain.  It will occur on every trial."

• 0

• 0.3

• 0.99

• 1

Probability is a measure of how likely an outcome is to occur.  Which of the following probability best matches the statement:  "This outcome is very unlikely, but it will occur every once in awhile in a long sequence of trials."

• 0.01

• 0.3

• 0.6

• 0.99

Probability is a measure of how likely an outcome is to occur.  Which of the following probability best matches the statement:  "This outcome will occur more often than not."

• 0.01

• 0.3

• 0.6

• 0.99

A number cube is rolled twice. What is the probability of getting a 6 on the first roll, then a number less than 5 on the second roll? 

• 2/3

• 5/36

• 1/9

• 1/36

The two spinners above are spun. What is the probability of getting a perfect square (1,4,9,16), then the letter Z? 

• 3/20

• 9/20

• 1/8

• 11/40

A standard die is rolled twice. Find each probability.

P (even, then less than 5)

• 1/2

• 1/3

• 2/3

• 1/9

A standard die is rolled twice. Find each probability.

P (prime, then 6)

• 1/2

• 2/3

• 1/9

• 1/12

A standard die is rolled twice. Find each probability.

P (the same number both times)

• 1/2

• 1/3

• 1/6

• 1/9