What does the standard deviation measure?a.Spread of datab.Central tendencyc.Skewness of datad.Variability of data

The standard deviation measures both a. Spread of data and d. Variability of data.

Step 1: Understanding the concept Standard deviation is a statistical measurement that shows how much variation or dispersion exists from the average (mean), or expected value.

Step 2: Spread of data A low standard deviation means that the data points tend to be very close to the mean, while a high standard deviation indicates that the data are spread out over a large range of values.

Step 3: Variability of data Standard deviation is also a measure of variability. When the values in a dataset are generally close to the mean, the standard deviation is small. When the values are spread out, the standard deviation is large.

So, the standard deviation is a measure of the amount of variation or dispersion of a set of values. It is not a measure of central tendency (which would be the mean, median, or mode), nor does it measure the skewness of data (which is a measure of the asymmetry of the probability distribution).