问题


There is a single choice question about high school statistics. Answer the question by replying A, B, C or D.
Question: An assembly line machine is supposed to turn out ball bearings with a diameter of 1.25 centimeters. Each morning the first 30 bearings produced are pulled and measured. If their mean diameter is under 1.23 centimeters or over 1.27 centimeters, the machinery is stopped and an engineer is called to make adjustments before production is resumed. The quality control procedure may be viewed as a hypothesis test with the null hypothesis H0: μ = 1.25 and the alternative hypothesis Ha: μ ≠ 1.25. The engineer is asked to make adjustments when the null hypothesis is rejected. In test terminology, what would a Type II error result in?
A. A warranted halt in production to adjust the machinery
B. An unnecessary stoppage of the production process
C. Continued production of wrong size ball bearings
D. Continued production of proper size ball bearings
Answer:

答案

模型 模型答案 正确答案
金声玉亮2.0

C. Continued production of wrong size ball bearings.

Explanation: A Type II error occurs when a false null hypothesis is not rejected. In this case, the null hypothesis is that the mean diameter of the ball bearings is 1.25 cm. If the true mean diameter is not 1.25 cm (e.g., it's actually 1.23 cm or 1.27 cm), but the test fails to reject the null hypothesis, then the machinery will not be adjusted, and the production of ball bearings with the wrong size will continue. This is a Type II error.

Note: The other options are not correct because:

A. A warranted halt in production to adjust the machinery would be a correct rejection of the null hypothesis (i.e., a correct decision to stop production and adjust the machinery).

B. An unnecessary stoppage of the production process would be a Type I error (i.e., rejecting a true null hypothesis).

D. Continued production of proper size ball bearings would be a correct failure to reject the null hypothesis (i.e., a correct decision to continue production).
C
deepseekr1

In hypothesis testing, a Type II error occurs when the null hypothesis (H₀) is not rejected even though it is false. In this scenario, H₀ states the mean diameter is 1.25 cm. If the machinery produces bearings with a mean diameter deviating from 1.25 cm (H₀ is false), but the sample mean (from the first 30 bearings) does not fall outside the 1.23–1.27 cm range, the test fails to detect the issue. Consequently, production continues despite the machinery producing bearings of the wrong size. This matches **Option C**, which describes the consequence of a Type II error.

**Answer:** C
C
gpto1 C C
GPT-4o C. Continued production of wrong size ball bearings C
llama3.1-70B-Instruct

C
C
llama3.1-405B-Instruct

C. Continued production of wrong size ball bearings.

Explanation: A Type II error occurs when a false null hypothesis is not rejected. In this case, the null hypothesis is that the mean diameter of the ball bearings is 1.25 cm. If the true mean diameter is not 1.25 cm (i.e., the null hypothesis is false), but the test fails to reject the null hypothesis, then the machinery will not be adjusted, and the production of ball bearings with the wrong size will continue. This is a Type II error.

The other options are incorrect because:

A. A warranted halt in production to adjust the machinery would be a correct decision, not an error.

B. An unnecessary stoppage of the production process would be a Type I error, not a Type II error.

D. Continued production of proper size ball bearings would be a correct decision, not an error.
C
DeepSeek-Coder-V2 C. Continued production of wrong size ball bearings C
Qwen2-72B-Instruct C. Continued production of wrong size ball bearings C
baichuan4 C C
doubao C

A Type II error is the failure to reject the null hypothesis when it is actually false. In this case, it would mean not stopping the machinery when the mean diameter is not actually 1.25 centimeters (i.e., continued production of wrong size ball bearings) even though it should have been stopped.
C
minimax C. Continued production of wrong size ball bearings C
kimi C. Continued production of wrong size ball bearings C
wenxinyiyan C. Continued production of wrong size ball bearings

Explanation:
In hypothesis testing, a Type II error occurs when we fail to reject the null hypothesis when it is actually false. In this context, the null hypothesis (H0) is that the mean diameter of the ball bearings is 1.25 centimeters. The alternative hypothesis (Ha) is that the mean diameter is not 1.25 centimeters.

A Type II error in this situation would mean that the machinery continues to produce ball bearings even when the mean diameter is not within the acceptable range (under 1.23 centimeters or over 1.27 centimeters). This would result in continued production of wrong size ball bearings, which is why option C is the correct answer.

Option A represents a correct decision to halt production when the mean diameter is out of range, so it is not a Type II error.
Option B represents a Type I error, which is when we reject the null hypothesis when it is actually true, leading to an unnecessary stoppage of the production process.
Option D represents a situation where the machinery is producing ball bearings of the proper size, so no error has occurred.
C
zhipu C. Continued production of wrong size ball bearings

A Type II error occurs when the null hypothesis is not rejected when it is actually false. In this context, that means the machinery is producing ball bearings with a mean diameter that is not 1.25 centimeters (either under 1.23 or over 1.27 centimeters), but the quality control procedure fails to detect this and allows production to continue. This results in the continued production of wrong size ball bearings.
C
gpto1 C C
deepseekv3 C. Continued production of wrong size ball bearings

Explanation: A Type II error occurs when the null hypothesis is not rejected when it is actually false. In this context, it means the machinery continues to produce ball bearings with a mean diameter different from 1.25 centimeters (either under 1.23 cm or over 1.27 cm), but the quality control procedure fails to detect this, leading to continued production of wrong size ball bearings.
C