Random Variables and Probability Quiz

Which of the following best defines a random variable?

• A number selected by the teacher

• A variable whose value is fixed

• A function that assigns a number to each outcome in a sample space

• A graph of data

What is the sample space when tossing a coin once?

• {Head}

• {Tail}

• {Head, Tail}

• {Head, Head}

Which of the following is a discrete random variable?

• The height of students in a class

• The time it takes to finish a race

• The number of books on a shelf

• The temperature in Manila

Which of these best describes a continuous random variable?

• Number of coins in your pocket

• Score in a multiple-choice quiz

• Weight of a watermelon

• Number of pets at home

A couple has three children. How many total possible outcomes are there for the gender of the children?

• 2

• 4

• 6

• 8

What are the possible values of the random variable X representing the number of heads when tossing 2 coins?

• 0, 1, 2

• H, T

• 1, 2

• HH, HT, TH, TT

What is the random variable in the scenario: “Counting the number of defective phones out of 3 tested units”?

• Type of phone

• Number of defective phones

• Brand of the phones

• Price of each phone

Which of the following is NOT a valid example of a random variable?

• Number of students in class

• Brand of a mobile phone

• Temperature in Tagaytay

• Height of a Grade 11 student

Which term refers to the entire group from which a sample is drawn?

• Estimate

• Variable

• Population

• Sample

Which refers to a subgroup taken from a population?

• Data

• Sample

• Parameter

• Variable