you don't actually need to do any of this stupid fake math, at least according to the OP's report, the questions and format of the test discredit it, he knew the questions going in and they were all formatted for him to give repeated "no" answers except for the last one which is actually an impossible question for him to answer
i don't even know what 65% or 90% accurate is supposed to mean, the polygraph makes no reading, it's the tester who determines it
unless they have one of those fancy machines like the Baltimore Police Department and a professor to operate it: