I can't figure this out... The pregnancy tests are 99% accurate, we have taken the test five times... what is the probability that we have received a false result five times?
My intuition is that every time you take the test, you have a 1% chance of receiving a false result... regardless of how many times you take the test. Just like tossing the dice. The previous toss has no bearing on the current toss. But, I can't reconcile that in my brain.
I haven't taken any classes in this type of thing.
No real pressure, it's just a question that's been bugging me. I can't figure it out, and that frustrates the hell out of me.
If they were independent events, then the chance of getting five false positives would be (0.01)*(0.01)*(0.01)*(0.01)*(0.01) or something like a billion to one odds.
About the only way you would get five false positives is if Amy were taking HCG because of fertility treatments or something.
I doubt that you could have bought five outdated tests, and I think false negatives would be more likely in that case than false positives.
I have used a lot of home pregnancy tests and the current ones on the market are pretty accurate if you buy a reliable brand and use them as directed.
Amy still will need to see a doctor, who will probably repeat the test and do some others as well, to figure out how far along she is and to start prenatal care, including prenatal vitamins.
When did her last period start?