A series of cylindrically shaped (l= 25 mm, d = 5 mm) ceramic samples are tested are testedin tension. The Weibull distribution coefficient is 5, and 50% of the samples fracture at a stress of 100MN/m^2 or less. Suppose we construct a cylindrical component of this material having a length l = 50 mm and diameter d = 10mm. It is required to have a survival probability for this structure of 95% when it is subjected to a tensile stress sigma prime. What is the allowable value of sigma prime?