Standard+Deviation

**Standard deviation is a statistical measure of spread or variability.The standard deviation is the root mean square (RMS) deviation of the values from their arithmetic mean.**   **Suppose your data follows the classic bell shaped curve pattern. One conceptual way to think about the standard deviation is that it is a measures of how spread out the bell is. Shown below is a bell shaped curve with a standard deviation of 1. Notice how tightly concentrated the distribution is.**




 * Shown below is a different bell shaped curve, one with a standard deviation of 2. Notice that the curve is wider, which implies that the data are less concentrated and more spread out. **




 * Finally, a bell shaped curve with a standard deviation of 3 appears below. This curve shows the most spread. **



Formula for Standard Deviation

Standard Deviation Activity