IBM Data Science Practice Test

If the variance of a data point is 16, what would be the standard deviation?

1. 4

2. 8

3. 16

4. 12

The correct answer is: 4

To determine the standard deviation from the variance, you take the square root of the variance. The variance is a measure of how much the data points deviate from the mean, expressed in squared units. In this case, if the variance is given as 16, the standard deviation would be calculated as follows: Standard Deviation = √Variance = √16 = 4. Thus, a standard deviation of 4 indicates that the data points are, on average, 4 units away from the mean. This relationship is fundamental in statistics, where the standard deviation is often more interpretable since it shares the same units as the data, whereas variance is expressed in squared units.