After the Gaussian distribution, the probability distribution most commonly used in evaluating uncertainty in measurement is the rectangular distribution. When the mid-point of a rectangular distribution is fixed but the half-width is uncertain and the probability distribution of the half-width can be represented by another rectangular probability distribution, the resulting distribution looks like a trapezoid whose sloping sides are curved. We can refer to such a distribution as curvilinear trapezoidal distribution. A symmetric curvilinear trapezoid is isocurvilinear. We discuss the properties of an isocurvilinear trapezoidal distribution which arises when the probability distribution of the half-width can be represented by another rectangular distribution. When the uncertainty in half-width is not excessive, the isocurvilinear trapezoidal distribution is well approximated by an isosceles trapezoidal distribution.
Pub Type: Journals
trapezoidal distribution, uncertainty in measurement