Paper × 841 mm). A1 is half the size of a sheet of A0 (i.e., 594 mm × 841 mm), such that two sheets of A1 placed side by side are equal to one sheet of A0. A2 is half the size of a sheet of A1, and so forth. Common sizes used in the office and the home are A4 and A3 (A3 is the size of two A4 sheets). The density of paper ranges from for tissue paper to for some speciality paper. Printing paper is about . Paper may be classified into seven categories: Some paper types include:
Folded-t and half-t distributions allowing for finite degrees-of-freedom (the normal analogues constitute the limiting cases of infinite degrees-of-freedom). Since the Cauchy distribution constitutes the special case of a Student-"t" distribution with one degree of freedom, the families of folded and half-"t" distributions include the folded Cauchy and half-Cauchy distributions for formula_5. If formula_3, the folded-"t" distribution reduces to the special case of the half-"t" distribution. Its probability density function then simplifies to The half-"t" distribution's first two moments (expectation and variance) are given by: and Folded-t and half-t distributions In statistics, the folded-"t" and half-"t" distributions are derived from Student's "t"-distribution by taking the