AN EXACT FORMULA FOR THE SYMMETRICAL INCOMPLETE BETA FUNCTION WHERE THE PARAMETER IS AN INTEGER OR HALF-INTEGER

A finite series for computing the symmetrical incomplete beta function with parameter q= 0.5, 1, 1.5, is derived. It is more efficient than existing algorithms for the general case, and obviates reference to the Pearson-Johnson tables and subsequent interpolation. This is advantageous in applications to statistical quality assurance, especially in computer simulations of acceptance schemes.