Final answer:
The standard deviation is a measure of how far the data are spread from the mean, providing a representative measure of dispersion.
Step-by-step explanation:
The standard deviation is a number that measures how far the data are spread from the mean. It tells us about the variation or dispersion of the data.
A) Mean deviation: This is a different measure of dispersion which is the average of the absolute differences of each data point from the mean. It is not the standard deviation.
B) Median deviation: This is similar to mean deviation but uses the median instead of the mean.
C) Absolute deviation: This is another measure of dispersion which is the average of the absolute differences of each data point from the mean. It is not the standard deviation.
D) Standard deviation: This is the most commonly used measure of dispersion which takes into account all the data points and their distances from the mean. It provides a more representative measure of how far the data are spread.=