In the context of displaying error bars on a graph, which quantity is most commonly used to represent the variability of the data?

• A. $\mathrm{Mean}$
• B. $\mathrm{Standard} \mathrm{deviation}$
• C. $\mathrm{Median}$
• D. $\mathrm{Mode}$

Answer: (B)

Verified step by step guidance

1. Understand that error bars on a graph are used to visually represent the variability or uncertainty in the data.
2. Recall that the mean, median, and mode are measures of central tendency, which describe the center of the data distribution, not its variability.
3. Recognize that the standard deviation is a measure of spread or dispersion, indicating how much the data points typically deviate from the mean.
4. Know that when displaying error bars, the standard deviation is commonly used because it provides a clear indication of the variability around the mean.
5. Therefore, the quantity most commonly used to represent variability in error bars is the standard deviation.