Canadian Society for Medical Laboratory Science (CSMLS) Practice Exam

What applies to standard deviation?

1. Expresses amount of variation around a mean value

2. Used in quality graphs

3. Used to calculate reference ranges

4. All the above

The correct answer is: All the above

Standard deviation is a statistical measurement that quantifies the amount of variation or dispersion in a set of values. It is essential in understanding how spread out or clustered the data points are around the mean. In terms of expressing variability, standard deviation indicates how much individual values differ from the mean. A smaller standard deviation suggests that the values tend to be closer to the mean, while a larger standard deviation indicates a wider spread of values. Additionally, standard deviation is often employed in quality control graphs, such as control charts, where it helps to monitor processes and maintain the quality of outputs by identifying variations that could indicate issues. Furthermore, standard deviation plays a crucial role in calculating reference ranges for various laboratory tests. Reference ranges are typically established using population data, and the standard deviation helps to determine the range in which most of the values will fall, assisting in the interpretation of individual test results. Thus, all of these aspects highlight the multifaceted role of standard deviation in statistical analysis within medical laboratory science, making the answer comprehensive and encompassing all the relevant applications.