问题


There is a single choice question about high school statistics. Answer the question by replying A, B, C or D.
Question: Which of the following is a binomial random variable?
A. The number of tosses before a "5" appears when tossing a fair die.
B. The number of points a hockey team receives in 10 games, where two points are awarded for wins, one point for ties, and no points for losses.
C. The number of hearts out of five cards randomly drawn from a deck of 52 cards, without replacement.
D. The number of motorists not wearing seat belts in a random sample of five drivers.
Answer:

答案

模型 模型答案 正确答案
金声玉亮2.0

D. The number of motorists not wearing seat belts in a random sample of five drivers.

Explanation: A binomial random variable is a discrete random variable that counts the number of successes in a fixed number of independent trials, where each trial has a constant probability of success. In this case, the number of motorists not wearing seat belts in a random sample of five drivers is a binomial random variable because:

* There are a fixed number of trials (5 drivers)
* Each trial has a constant probability of success (a driver not wearing a seatbelt)
* The trials are independent (the outcome of one driver does not affect the outcome of another)
* The random variable counts the number of successes (drivers not wearing seatbelts)
D
deepseekr1

To determine which option is a binomial random variable, recall the criteria: fixed number of trials, independent trials, two outcomes (success/failure), and constant probability of success.

- **A** describes the number of trials until the first success (geometric distribution), not binomial.
- **B** involves three possible outcomes per game (win, tie, loss), violating the binary outcome requirement.
- **C** involves sampling without replacement, leading to dependent trials and non-constant probabilities (hypergeometric distribution).
- **D** counts successes (not wearing seat belts) in a fixed sample of five drivers. Assuming independence and constant probability (reasonable for a large population), this fits a binomial model.

**Answer: D**
D
gpto1 D D
GPT-4o D. The number of motorists not wearing seat belts in a random sample of five drivers. D
llama3.1-70B-Instruct

D
D
llama3.1-405B-Instruct

D. The number of motorists not wearing seat belts in a random sample of five drivers.
D
DeepSeek-Coder-V2 D D
Qwen2-72B-Instruct D. The number of motorists not wearing seat belts in a random sample of five drivers. D
baichuan4 B D
doubao D

A binomial random variable has the following properties: there are a fixed number of independent trials, each trial has only two possible outcomes (success or failure), and the probability of success is the same for each trial. Option D satisfies these conditions as there are a fixed number of 5 drivers (trials), each driver either wears a seat belt (success) or doesn't (failure), and the probability of a driver not wearing a seat belt is assumed to be the same for each driver. Option A doesn't have a fixed number of trials until a "5" appears. Option B has more than two possible outcomes (0, 1, 2, etc. points). Option C doesn't have independent trials as the cards are drawn without replacement.
D
minimax C. The number of hearts out of five cards randomly drawn from a deck of 52 cards, without replacement. D
kimi D. The number of motorists not wearing seat belts in a random sample of five drivers.

A binomial random variable is defined by two conditions:
1. There are a fixed number of trials (n).
2. Each trial has only two possible outcomes, typically labeled as "success" and "failure", and the probability of success (p) is the same for each trial.

Option D fits this definition because:
- There is a fixed number of trials (n = 5 drivers).
- Each trial (checking a driver) has two possible outcomes (wearing a seat belt or not wearing a seat belt), and the probability of not wearing a seat belt is the same for each driver.

Options A, B, and C do not fit the definition of a binomial random variable because:
- Option A involves a geometric distribution, not a binomial one, as it deals with the number of trials until a specific outcome occurs.
- Option B involves a variable number of outcomes (0, 1, or 2 points) per trial, not just two.
- Option C involves a hypergeometric distribution, as it deals with drawing without replacement, which affects the probability of drawing a heart on each draw.
D
wenxinyiyan D

Explanation:
A binomial random variable satisfies the following conditions:

1. The experiment consists of a fixed number of trials, n.
2. Each trial has only two possible outcomes, often called "success" and "failure".
3. The probability of success, p, is the same for each trial.
4. The trials are independent.

Let's evaluate each option:

A. The number of tosses before a "5" appears when tossing a fair die.
- This does not have a fixed number of trials, so it violates condition 1.

B. The number of points a hockey team receives in 10 games, where two points are awarded for wins, one point for ties, and no points for losses.
- There are more than two possible outcomes (2 points, 1 point, 0 points), so it violates condition 2.

C. The number of hearts out of five cards randomly drawn from a deck of 52 cards, without replacement.
- The trials are not independent because removing a card changes the probabilities for the remaining cards. This violates condition 4.

D. The number of motorists not wearing seat belts in a random sample of five drivers.
- This satisfies all four conditions:
1. There are a fixed number of trials (5 drivers).
2. Each trial has only two possible outcomes (wearing a seat belt or not).
3. The probability of a motorist not wearing a seat belt is assumed to be the same for each driver in the sample.
4. The trials are independent (assuming one driver's behavior doesn't affect another's).
D
zhipu D

Explanation:
A binomial random variable is defined by the following criteria:
1. There are a fixed number of trials (n).
2. Each trial has two possible outcomes, often labeled as "success" and "failure."
3. The probability of success (p) is the same for each trial.
4. The trials are independent of each other.

Let's analyze each option:

A. The number of tosses before a "5" appears when tossing a fair die.
- This does not have a fixed number of trials, and the probability of success (getting a "5") changes with each toss. This is a geometric random variable, not a binomial.

B. The number of points a hockey team receives in 10 games, where two points are awarded for wins, one point for ties, and no points for losses.
- This scenario involves more than two outcomes per game (win, tie, loss), so it does not fit the binomial criteria.

C. The number of hearts out of five cards randomly drawn from a deck of 52 cards, without replacement.
- The trials are not independent because the probability of drawing a heart changes after each card is drawn without replacement. This is a hypergeometric random variable, not a binomial.

D. The number of motorists not wearing seat belts in a random sample of five drivers.
- This fits the binomial criteria: there are a fixed number of trials (5 drivers), each driver can either be wearing a seat belt (failure) or not wearing a seat belt (success), the probability of not wearing a seat belt is the same for each driver, and the trials are independent.

Therefore, the correct answer is D.
D
gpto1 D D
deepseekv3 The correct answer is:

**C. The number of hearts out of five cards randomly drawn from a deck of 52 cards, without replacement.**

### Explanation:
A binomial random variable must satisfy the following conditions:
1. There are a fixed number of trials (n).
2. Each trial has only two possible outcomes: success or failure.
3. The probability of success (p) is the same for each trial.
4. The trials are independent.

Let's analyze the options:
- **A:** This is not binomial because the number of trials is not fixed; it depends on when the first "5" appears.
- **B:** This is not binomial because the number of points awarded varies (2 for a win, 1 for a tie, 0 for a loss), and there are more than two possible outcomes.
- **C:** This is binomial because there are 5 trials (drawing 5 cards), each card is either a heart (success) or not (failure), the probability of drawing a heart is the same for each card (13/52 = 1/4), and the trials are independent (assuming the deck is large enough that the change in probability is negligible).
- **D:** This is not binomial because the trials are not independent; the probability of a motorist not wearing a seat belt may vary depending on the sample.

Thus, the correct answer is **C**.
D