Question

Thank you in advance
In a 2020 statistic shows that 50% of women age 20 and younger have taken a pregnancy test and 30% of those who have taken a pregnancy test are or have been pregnant. Over the counter pregnancy tests give a false positive 5% of the time and a false negative 13% of the time.
1). Assuming that none of the women who did not take a pregnancy test were pregnant, what percentage of women age 20 and under are or have been pregnant?
2) Given that a woman took a pregnancy test, what is the probability that she had a false negative test?
3) For a woman who received a negative pregnancy test, what is the probability she actually was pregnant?
4) For a woman who received a positive pregnancy test, what is the probability that she was not pregnant?

Answer 1

I have seen your repeated questions. Clearly, no one watching here feels confident in their ability to answer. I took a statistics class 50 years ago, and I'm sure if I pored over the matter again, I could figure it out, but that's too much trouble. Surely by this time you could have found similar exercises in your text, or online.

But I guess that's too much trouble for you, too.

Answer 2

I have tried looking at similar answers and I am not sure I am correct... and I am not a mind reader to know you don't feel confident....thanks anyway ..didn't mean for you to be too troubled

Answer 3

1).5*.3=.15=15%, multiply percent of <20 age women times percent that are pregnant
2)13%, from problem
3)False negative means the result is irrelevant. Therefore, percentage is 30%
4)70%, same reasoning as above