问题


There is a single choice question about high school statistics. Answer the question by replying A, B, C or D.
Question: A soft drink dispenser can be adjusted to deliver any fixed number of ounces. If the machine is operating with a standard deviation in delivery equal to 0.3 ounce, what should be the mean setting so that a 12-ounce cup will overflow less than 1% of the time? Assume a normal distribution for ounces delivered.
A. 12 - 0.99(0.3) ounces
B. 12 - 2.326(0.3) ounces
C. 12 - 2.576(0.3) ounces
D. 12 + 2.326(0.3) ounces
Answer:

答案

模型 模型答案 正确答案
金声玉亮2.0

B. 12 - 2.326(0.3) ounces

Reasoning:

This question requires the application of the normal distribution and the concept of z-scores. The problem states that the machine should be adjusted so that a 12-ounce cup will overflow less than 1% of the time. This means that the probability of overflowing should be less than 0.01.

Using a standard normal distribution table (also known as a z-table), we can find the z-score corresponding to a probability of 0.01. The z-score is approximately 2.326.

The formula to find the mean setting is:

Mean = 12 - (z-score x standard deviation)

Substituting the values, we get:

Mean = 12 - (2.326 x 0.3)
Mean = 12 - 0.6978
Mean ≈ 11.30

Therefore, the correct answer is B. 12 - 2.326(0.3) ounces.
B
deepseekr1

To ensure a 12-ounce cup overflows less than 1% of the time, we need the mean (μ) such that \( P(X > 12) < 0.01 \). This corresponds to the 99th percentile of the normal distribution (where 99% of deliveries are ≤12 ounces). The z-score for the 99th percentile is approximately 2.326. Using the formula \( z = \frac{X - \mu}{\sigma} \):

\[
2.326 = \frac{12 - \mu}{0.3}
\]

Solving for μ:

\[
\mu = 12 - 2.326 \times 0.3
\]

Thus, the correct mean setting is **B. 12 - 2.326(0.3) ounces**.

**Answer:** B
B
gpto1 B B
GPT-4o To ensure that a 12-ounce cup overflows less than 1% of the time, we need to set the mean such that the probability of the delivery exceeding 12 ounces is less than 1%.

In a normal distribution, the z-score corresponding to the cumulative probability of 0.99 (since we want less than 1% overflow) is approximately 2.326.

The z-score formula is:
\[ z = \frac{X - \mu}{\sigma} \]

Here:
- \( X \) is the value we are interested in (12 ounces),
- \( \mu \) is the mean setting we need to find,
- \( \sigma \) is the standard deviation (0.3 ounces).

Rearranging the formula to solve for \( \mu \):
\[ \mu = X - (z \cdot \sigma) \]

Substitute the known values:
\[ \mu = 12 - (2.326 \cdot 0.3) \]

So:
\[ \mu = 12 - 0.6978 \]
\[ \mu \approx 11.3022 \]

Therefore, the mean setting should be:
\[ 12 - 2.326(0.3) \]

The correct answer is:
B. 12 - 2.326(0.3) ounces
B
llama3.1-70B-Instruct

B
B
llama3.1-405B-Instruct

B. 12 - 2.326(0.3) ounces

Reasoning:

To find the mean setting so that a 12-ounce cup will overflow less than 1% of the time, we need to find the z-score corresponding to the 99th percentile (since 1% is equivalent to the area to the right of the z-score).

Using a standard normal distribution table or calculator, we find that the z-score corresponding to the 99th percentile is approximately 2.326.

Since the standard deviation is 0.3 ounces, we can set up the following equation:

z = (X - μ) / σ

where X is the value we want to find (the mean setting), μ is the mean, and σ is the standard deviation.

Rearranging the equation to solve for X, we get:

X = μ + zσ

Since we want the cup to overflow less than 1% of the time, we want the mean setting to be less than 12 ounces. Therefore, we subtract the product of the z-score and standard deviation from 12:

X = 12 - 2.326(0.3)

This corresponds to option B.

Note: Options A, C, and D are incorrect because they do not use the correct z-score or calculation.
B
DeepSeek-Coder-V2 C. 12 - 2.576(0.3) ounces B
Qwen2-72B-Instruct B. 12 - 2.326(0.3) ounces B
baichuan4 C B
doubao B

To find the mean setting so that a 12-ounce cup will overflow less than 1% of the time, we need to find the z-score corresponding to the 99th percentile (1 - 0.01 = 0.99). Looking up the z-score for the 99th percentile in a standard normal distribution table gives approximately 2.326. The mean should be set at 12 minus the z-score times the standard deviation, so 12 - 2.326(0.3) ounces.
B
minimax To solve this problem, we need to find the mean setting such that the probability of the dispenser delivering more than 12 ounces is less than 1%. Since we are dealing with a normal distribution, we can use the Z-score to find the value that corresponds to the upper tail of 1%.

The Z-score that corresponds to the upper 1% tail of a normal distribution is approximately 2.326 (this is the Z-score for a one-tailed test with a significance level of 0.01).

We want the mean setting to be such that 12 ounces is 2.326 standard deviations above the mean. The formula to find the mean setting (μ) is:

μ = X - Z * σ

where:
- X is the desired value (12 ounces in this case),
- Z is the Z-score (2.326),
- σ is the standard deviation (0.3 ounces).

Plugging in the values:

μ = 12 - 2.326 * 0.3
μ = 12 - 0.6978
μ ≈ 11.3022 ounces

The closest answer choice to our calculation is:

B. 12 - 2.326(0.3) ounces

So the correct answer is B.
B
kimi To answer this question, we need to determine the z-score that corresponds to the 99th percentile of a standard normal distribution because we want the overflow to occur less than 1% of the time. The z-score for the 99th percentile is approximately 2.326.

Given that the standard deviation (σ) is 0.3 ounces, we can calculate the mean (μ) setting for the dispenser as follows:

Mean setting = Desired amount - (z-score * standard deviation)
Mean setting = 12 - (2.326 * 0.3)

Now, let's calculate the mean setting:

Mean setting = 12 - (2.326 * 0.3)
Mean setting = 12 - 0.6978
Mean setting ≈ 11.3022 ounces

So, the correct answer is:
B. 12 - 2.326(0.3) ounces
B
wenxinyiyan C B
zhipu To determine the mean setting for the soft drink dispenser so that a 12-ounce cup will overflow less than 1% of the time, we need to use the properties of the normal distribution.

Given:
- Standard deviation (\(\sigma\)) = 0.3 ounces
- Overflow probability = 1% (or 0.01)

We need to find the z-score that corresponds to the 99th percentile of the normal distribution (since 1% overflow means 99% of the time the cup should not overflow).

From standard normal distribution tables or a z-score calculator, the z-score for the 99th percentile is approximately 2.326.

The formula to relate the mean (\(\mu\)), standard deviation (\(\sigma\)), and the z-score is:
\[ X = \mu + z\sigma \]

Where \(X\) is the value at which we want the probability to be less than 1% (in this case, 12 ounces).

Rearranging the formula to solve for \(\mu\):
\[ \mu = X - z\sigma \]

Substituting the values:
\[ \mu = 12 - 2.326 \times 0.3 \]

So, the correct option is:
B. 12 - 2.326(0.3) ounces

Answer: B
B
gpto1 B B
deepseekv3 To solve this problem, we need to determine the mean setting of the soft drink dispenser such that a 12-ounce cup overflows less than 1% of the time. We are given that the standard deviation (σ) of the delivery is 0.3 ounces, and we assume a normal distribution.

### Step-by-Step Solution:

1. **Understand the Problem:**
- We want the probability that the dispenser delivers more than 12 ounces to be less than 1%.
- This means we need to find the mean (μ) such that P(X > 12) < 0.01.

2. **Convert to a Z-Score:**
- We use the standard normal distribution to find the corresponding z-score for the 99th percentile (since we want less than 1% in the tail).
- The z-score for the 99th percentile is approximately 2.326.

3. **Set Up the Inequality:**
- We want P(X > 12) < 0.01, which translates to:
\[
Z = \frac{12 - \mu}{\sigma} > 2.326
\]
- To ensure P(X > 12) < 0.01, we set:
\[
\frac{12 - \mu}{0.3} = 2.326
\]

4. **Solve for μ:**
\[
12 - \mu = 2.326 \times 0.3
\]
\[
\mu = 12 - 2.326 \times 0.3
\]

5. **Calculate the Mean:**
\[
\mu = 12 - 0.6978 \approx 11.3022 \text{ ounces}
\]

### Conclusion:
The mean setting should be \( 12 - 2.326 \times 0.3 \) ounces to ensure that the 12-ounce cup overflows less than 1% of the time.

**Answer:** B. 12 - 2.326(0.3) ounces
B