CompTIA Data+ (DA0-002)Data AnalysisMedium
A data analyst is examining a dataset of employee salaries. The salaries are known to be right-skewed, meaning a few highly paid executives significantly inflate the average. The analyst wants to report a measure of central tendency that is resistant to these extreme values, providing a better representation of what a 'typical' employee earns. Which of the following descriptive statistics should they use?
- AMode
- BMedian
- CMean
- DRange
Show answer & explanationAnswer & explanation
Correct answer: B. Median
The median is the middle value in a sorted dataset, making it resistant to outliers and extreme values. For skewed distributions like salaries with high earners, the median provides a more accurate representation of the 'typical' value than the mean.
Why the other options are wrong
- A. The mode is the most frequent value, which might not be representative of the central tendency for continuous data like salaries and can be multiple or non-existent.
- C. The mean is highly sensitive to extreme values and would be inflated by the high salaries.
- D. Range describes the spread of data, not its central tendency.
Robustness of Median
The median's ability to remain largely unchanged by extreme values (outliers) in a dataset, making it a robust measure of central tendency for skewed distributions.
- Unaffected by magnitude of outliers, only their position.
- Preferred for income, property values, or other skewed distributions.
- Contrasts with the mean, which is pulled by outliers.
Memory trick: Median for money, because it's not swayed by the rich.