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AP Statistics Practice Quiz: Estimating Probabilities Using Simulation

Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026

Test your understanding with short quizzes. This quiz has 14 questions to check your progress.

Question 1 of 14

Which of the following best describes a random process?

All Questions (14)

Which of the following best describes a random process?

A) A process with a predictable, predetermined result.

B) A process where results are determined by chance.

C) A collection of specific outcomes.

D) A model used to estimate probabilities.

Correct Answer: B

Based on the provided content, 'A random process generates results determined by chance.'

According to the provided text, what is the primary purpose of a simulation in the context of probability?

A) To determine the true probability of an event with certainty.

B) To model random events in order to estimate their probabilities.

C) To list every possible outcome of a random process.

D) To prove that an event is not random.

Correct Answer: B

The text states, 'Simulation is a way to model random events,' and its purpose is to use the results to estimate probabilities.

A standard six-sided die is rolled once. The result is a '4'. Which term from the provided text best describes this single result?

A) An event

B) A simulation

C) An outcome

D) A random process

Correct Answer: C

The content defines an outcome as 'the result of a trial of a random process.' Rolling a '4' is the specific result of the single trial (the roll).

A coin is flipped three times. The event of interest is 'getting at least two heads.' Which of the following is the best description of this event?

A) The single outcome of flipping Heads, Tails, Heads (HTH).

B) The collection of outcomes: {HHT, HTH, THH, HHH}.

C) The random process of flipping a coin three times.

D) The law of large numbers.

Correct Answer: B

The content states that 'An event is a collection of outcomes.' The event 'getting at least two heads' includes all possible outcomes that satisfy this condition.

A researcher simulates flipping a biased coin 200 times and observes 130 heads. What is the estimated probability of getting heads based on the relative frequency from this simulation?

A) 0.35

B) 0.50

C) 0.65

D) 1.30

Correct Answer: C

The content states that 'The relative frequency of an event in a simulation can be used to estimate its probability.' The relative frequency is the number of times the event occurred (130) divided by the total number of trials (200), which is 130/200 = 0.65.

According to the law of large numbers, what happens to the estimated probability of an event as the number of trials in a simulation significantly increases?

A) It becomes more random and less predictable.

B) It tends to get closer to the true probability of the event.

C) It will always be equal to exactly 0.5.

D) It will decrease, regardless of the event.

Correct Answer: B

The provided content explicitly states, 'The law of large numbers states that empirical probabilities approach true probabilities as the number of trials increases.'

Two students are simulating the roll of a fair six-sided die to estimate the probability of rolling an even number. Student A performs 20 trials, while Student B performs 2,000 trials. According to the law of large numbers, which statement is most likely to be true?

A) Student A's estimated probability will be closer to the true probability (0.5) than Student B's.

B) Student B's estimated probability will be closer to the true probability (0.5) than Student A's.

C) Both students will get an estimated probability of exactly 0.5.

D) Student A and Student B will have identical estimated probabilities.

Correct Answer: B

The law of large numbers states that as the number of trials increases, the empirical (estimated) probability will get closer to the true probability. Since Student B performed significantly more trials, their estimate is more likely to be accurate.

In a simulation of rolling a fair die, a computer generates a random integer from 1 to 6. The number '2' is generated. This single result is best defined as:

A) An event

B) A simulation

C) A random process

D) An outcome

Correct Answer: D

The content defines an outcome as 'the result of a trial of a random process.' The number '2' is the specific result from a single trial (the computer generating a number).

A simulation is conducted to estimate the probability of a family with four children having exactly two boys. The simulation is run 500 times. The event 'exactly two boys' occurs 185 times. What is the empirical probability based on this simulation?

A) 0.250

B) 0.370

C) 0.500

D) 2.700

Correct Answer: B

The empirical probability is estimated using the relative frequency from the simulation. This is calculated as the number of times the event occurred (185) divided by the total number of trials (500), which is 185/500 = 0.37.

A student runs a simulation with only 15 trials to estimate the probability of a spinner landing on 'Red'. The simulation results in 9 'Red' outcomes. Why might this empirical probability of 0.6 be a poor estimate of the true probability?

A) The simulation was not a random process.

B) The number of trials is too small for the law of large numbers to suggest the estimate is close to the true probability.

C) An event cannot be a collection of outcomes.

D) The relative frequency can only be calculated with more than 100 trials.

Correct Answer: B

The law of large numbers states that the empirical probability approaches the true probability as the number of trials increases. With only 15 trials, the result is highly subject to chance variation and may not be close to the true probability.

Which of the following is the best definition of an event?

A) The result of a single trial of a random process.

B) A process where results are determined by chance.

C) A collection of one or more outcomes.

D) A model used to represent a random process.

Correct Answer: C

The provided content explicitly states that 'An event is a collection of outcomes.'

A factory estimates that 2% of its microchips are defective. A simulation is run to estimate the probability of finding at least one defective chip in a box of 50. After 500,000 trials, the relative frequency of this event is 0.636. What does this result suggest?

A) The simulation is flawed because the result (0.636) is not equal to the individual defect rate (0.02).

B) The true probability of finding at least one defective chip in a box of 50 is likely close to 0.636.

C) The simulation needs fewer trials to be accurate.

D) The random process of a chip being defective is not actually random.

Correct Answer: B

Due to the very large number of trials (500,000), the law of large numbers implies that the empirical probability (relative frequency) of 0.636 is a very good estimate of the true probability for the specified event (at least one defect in 50).

Which of the following scenarios describes a random process?

A) Calculating the sales tax on a $50 purchase.

B) Flipping a fair coin.

C) Following a set of instructions to assemble furniture.

D) Determining the boiling point of water at sea level.

Correct Answer: B

A random process generates results determined by chance. Flipping a coin has a chance-based result. The other options have predetermined, calculated results.

A student knows the answer to 75% of questions on a quiz. To estimate the probability of getting two consecutive questions correct, which is a valid way to conduct one trial of a simulation?

A) Roll a six-sided die twice. A roll of 1, 2, 3, or 4 means a correct answer.

B) Flip a coin twice. Heads means correct, tails means incorrect.

C) Use a random number generator to pick two integers from 1 to 4. For each integer, a 1, 2, or 3 represents a correct answer.

D) Use a random number generator to pick one integer from 1 to 4. A 1, 2, or 3 means both answers were correct.

Correct Answer: C

This simulation correctly models the random process for each of the two questions. It uses a 3/4 = 75% chance for a correct answer and repeats it twice to simulate the event. Option A has the wrong probability (4/6 ≈ 67%). Option B has the wrong probability (50%). Option D incorrectly models only one event for the two questions instead of two separate events.