High School Probability Quiz

Which of the following is a discrete random variable?

• The weight of a newborn baby.

• The height of a sunflower.

• The number of cars in a parking lot.

• The temperature of a room.

• The amount of rainfall in a city.

If a single die is rolled, which is NOT a possible value of the random variable representing the outcome?

• 1

• 3

• 5

• 7

• 6

Which formula could represent a probability distribution, given the condition that the sum of probabilities equals 1?

• P(X) = X/6 (where X = 1, 2, 3)

• P(X) = X/10 (where X = 1, 2, 3, 4)

• P(X) = 1/X (where X = 1, 2, 3)

• P(X) = 1/(X+1) (where X = 0, 1, 2)

• P(X) = X/(X+1) (where X = 1, 2, 3)

Which statement about probability distributions is FALSE?

• The probability of each outcome must be between 0 and 1, inclusive.

• The sum of probabilities for all possible outcomes must equal 1.

• A probability distribution can only describe discrete random variables.

• A probability distribution describes the likelihood of each possible value of a random variable.

• Zero probability is possible for a specific outcome.

If P(X) = k, where k is a constant, what value of k would make this a valid probability distribution for a single outcome?

• 0.2

• 1

• 0.5

• 2

• 0

Which of the following is an example of a continuous random variable?

• The number of students in a class.

• The number of heads when flipping three coins.

• The time it takes to complete a marathon.

• The number of defective items in a batch.

• The number of votes a candidate receives.

A variable whose value is a numerical outcome of a random phenomenon is called a:

• Constant

• Statistic

• Random variable

• Parameter

• Deterministic variable

Two dice are rolled. How many possible outcomes are there?

• 6

• 12

• 36

• 18

• 24

The sum of the probabilities in a probability distribution must always equal:

• 0

• 0.5

• 1

• The number of outcomes

• Infinity

The collection of all possible outcomes of a random experiment is called the:

• Event

• Sample space

• Probability

• Random variable

• Frequency