In certain conditions, the Confidence Interval for One Proportion calculator, available in the JMP® Sample Data Index, gives incorrect confidence intervals. These conditions are when the Number of Successes (x) equals the Sample Size (n), and when the Number of Successes equals 0. The alpha level should be divided by 2 in these cases, so, to get the correct calculations, change the Confidence Level value to (1 - alpha/2) rather than (1 - alpha).
[Previously JMP Note 68507]