[statistics] also bell-shaped normal curve, or bell-shaped distribution. when the class width in a histogram become sufficiently small, the frequency polygon may be approximated by a smooth curve, that is, the normal curve. Note: most common normal curve is mesokurtic(normal) distribution; if the curve has a sharp peak, it has a leptokurtic(peaky) distribution; if the curve is relatively flat, it has a platykurtic(flat) distribution.
