问题


There is a single choice question about high school statistics. Answer the question by replying A, B, C or D.
Question: For a class project, Charlotte recorded the heights of all 28 students in her class and calculated several statistics. She then realized she made an error recording the height of the tallest person in the class. She correctly had him listed as the tallest, but needed to add two inches to his recorded height to correct it. Which of these measures of spread must remain unchanged?
A. Mean absolute deviation
B. Standard deviation
C. Variance
D. Interquartile range
Answer:

答案

模型 模型答案 正确答案
金声玉亮2.0

D. Interquartile range.

The interquartile range (IQR) is the difference between the third quartile (Q3) and the first quartile (Q1). Since the error only affected the tallest person in the class, it will not affect the first quartile (Q1) or the third quartile (Q3) as long as the corrected height is still the tallest. Therefore, the IQR will remain unchanged.

The other options are incorrect because:

A. Mean absolute deviation (MAD) will change because the mean will change when the tallest person's height is corrected.

B. Standard deviation will change because the variance will change when the tallest person's height is corrected.

C. Variance will change because the sum of the squared differences from the mean will change when the tallest person's height is corrected.
D
deepseekr1

The question asks which measure of spread remains unchanged when correcting the tallest student's height. Measures like **mean absolute deviation (MAD)**, **standard deviation**, and **variance** depend on deviations from the mean. Increasing the tallest height raises the mean slightly, altering deviations for all data points. The tallest point's deviation increases more significantly, affecting these measures.

**Interquartile range (IQR)**, however, is based on quartiles (Q3 - Q1). Since quartiles depend on the middle 50% of data and the correction only affects the maximum value (outside the range influencing Q3), the quartiles themselves remain unchanged. Thus, the IQR stays the same.

**Answer: D**
D
gpto1 D D
GPT-4o D. Interquartile range D
llama3.1-70B-Instruct

D
D
llama3.1-405B-Instruct

D. Interquartile range (IQR) is a measure of spread that is not affected by changes in the extreme values (outliers) of a dataset, as long as the median and the first and third quartiles (Q1 and Q3) remain the same. Since the tallest person in the class was already correctly listed as the tallest, adding two inches to his recorded height does not change the median, Q1, or Q3. Therefore, the IQR remains unchanged.

The other options are incorrect because:

A. Mean absolute deviation (MAD) is affected by changes in the extreme values of a dataset.

B. Standard deviation is also affected by changes in the extreme values of a dataset.

C. Variance is the square of the standard deviation, so it is also affected by changes in the extreme values of a dataset.
D
DeepSeek-Coder-V2 D. Interquartile range D
Qwen2-72B-Instruct D. Interquartile range D
baichuan4 D D
doubao D

The interquartile range is based on the quartiles and is not affected by a change in a single extreme value. The mean absolute deviation, standard deviation, and variance are all affected by changes in individual values, including the correction of the tallest person's height.
D
minimax D. Interquartile range

The interquartile range (IQR) is the difference between the first quartile (Q1) and the third quartile (Q3) in a data set. It measures the middle spread of the data, excluding the highest 25% and the lowest 25% of the values. Since adding a constant to a single value (the tallest student's height in this case) does not affect the order of the middle 50% of the data, the IQR will remain unchanged.
D
kimi D. Interquartile range

The interquartile range (IQR) is the difference between the third quartile (Q3) and the first quartile (Q1). Since the IQR is based on the middle 50% of the data, and the error in recording the tallest student's height does not affect the middle 50% of the data, the IQR will remain unchanged. The other measures of spread (mean absolute deviation, standard deviation, and variance) are affected by changes in the values of the data, especially changes in extreme values like the tallest student's height.
D
wenxinyiyan D D
zhipu D. Interquartile range

The interquartile range (IQR) measures the spread of the middle 50% of the data and is calculated as the difference between the third quartile (Q3) and the first quartile (Q1). Since the tallest person's height, which is an extreme value, is only adjusted, it does not affect the positions of Q1 and Q3, and hence the IQR remains unchanged. The other measures (mean absolute deviation, standard deviation, and variance) are sensitive to changes in individual data points, including extreme values, and would be affected by the correction.
D
gpto1 D D
deepseekv3 The correct answer is:

**D. Interquartile range**

Explanation: The interquartile range (IQR) measures the spread of the middle 50% of the data and is based on the first quartile (Q1) and the third quartile (Q3). Since the tallest student's height is already the maximum value, increasing it does not affect Q1 or Q3, so the IQR remains unchanged. The other measures (mean absolute deviation, standard deviation, and variance) are all affected by changes in individual data points, especially extreme values like the maximum.
D