When calculating the Weibull cumulative distribution, an additional set of brackets has to be entered into the formula. This set of brackets is in excess of what is needed if standard calculation priorities were observed.

correct result produced if =exp(-((a/b)^c))
expected response          =exp(-(a/b)^c)

i.e. with standard calculation priorities active, there would be no need to enclose <(a/b)^c> in separate brackets, as exponents <^c> are supposed to be evaluated before quotients <a/b> and quotients before additions <represented here by the minus sign>. Brackets should be needed only where deviations from standard priorities are needed.