The standard deviation is used to measure the spread of values in a sample.
The higher the value for the standard deviation, the more spread out the values are in a sample. Conversely, the lower the value for the standard deviation, the more tightly packed together the values are.
The standard deviation is important because it tells us how spread out the values are in a given dataset.
Therefore, the last option is correct: The standard deviation will aid in predicting the range that will contain most of the data in a set.