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The overall pattern of a distribution can often be described compactly by a density curve. A density curve has total area 1 underneath it. Areas under a density curve give proportions of observations for the distribution.

The mean μ (balance point), the median (equal-areas point), and the quartiles can be approximately located by eye on a density curve. The standard deviation σ cannot be located by eye on most density curves. The mean and median are equal for symmetric density curves, but the mean of a skewed curve is located farther toward the long tail than is the median.