When the calculator whispered the variance—31.76—Marisol let out a short laugh, surprised by how human the number sounded to her. It was tangible, a measure of how wildly or calmly the class had swayed. But she was not done. Standard deviation demanded the square root, a smoothing out of the exaggerated squarings back into the units she recognized. MVSD obliged, displaying 5.64 and, in that instant, the whole dataset re-centered itself in her mind.
