Question 18

The mean changed from last year to this year.

The mean is the average of a set of numbers and is influenced by every value in the data set. Changes in individual data points can cause the mean to vary significantly from one year to the next.

A) Mean

The mean is a statistical measure that represents the average value of a data set. Since the question specifically asks which measure changed, and the mean can fluctuate based on the values within the data set, it is the correct answer.

B) Median

The median is the middle value of a data set when arranged in order. While it can change, it is less sensitive to extreme values than the mean. If the distribution of data points remained relatively stable, the median might not have changed, making it an incorrect choice for this question.

C) Mode

The mode refers to the most frequently occurring value in a data set. Unless there was a significant shift in the frequency of values, the mode is likely to remain the same, indicating it did not change from last year to this year.

D) Range

The range is the difference between the maximum and minimum values in a data set. Although it can change if the extreme values shift, there’s no indication in the question that suggests this measure specifically changed, thus making it an incorrect choice.

Conclusion

The mean is the only measure among the options that can change significantly due to fluctuations in the data points, making it the definitive answer. The median, mode, and range may remain stable unless specific alterations occur in the data set, which is not implied in the question. Therefore, option A is the only viable answer.