Standard deviation (SD) is a statistical measure of how spread out a set of data is. It is calculated by taking the square root of the variance, which is the average of the squared differences between each data point and the mean. SD is a useful measure of variability because it is expressed in the same units as the original data. This makes it easy to interpret and compare SDs from different datasets. For example, if you have a dataset of heights and the SD is 2 inches, this means that most people in the dataset are within 2 inches of the average height. SD can be used in a variety of applications, such as: Quality control: SD can be used to monitor the quality of a manufacturing process by tracking the SD of the product's dimensions. Finance: SD is used to measure the volatility of an investment, which is a measure of how much its price fluctuates. Research: SD is used in a variety of research fields to measure the variability of data, such as the variability of test scores or the variability of gene expression levels. Here are some examples of how SD can be used in a sentence: The SD of the test scores was 10 points. The SD of the stock price was 5%. The SD of the gene expression levels was 2-fold. SD is a powerful tool that can be used to understand and interpret data. By understanding SD, you can better understand the variability of data and make more informed decisions. What is the history of standard deviation? What is variance in simple words? What is the standard deviation symbol called? Ask a follow up