> In male mice, the drug caused infertility and was 99% effective in preventing pregnancies within four weeks of use.
I don't know if they mean 99% reduction compared to normal or 99% of mice did not cause a pregnancy. Either way this does not mean that every intercourse has a 1% chance of causing a pregnancy.
Also you are assuming an unconditional probability. It could very well be a conditional probability. It might completely work for 99% that do not cause any pregnancies at all and not work for 1% that cause pregnancies as without the drug.
Anyway I am looking forward to getting the perl index for humans from clinical trials.
I don't know if they mean 99% reduction compared to normal or 99% of mice did not cause a pregnancy. Either way this does not mean that every intercourse has a 1% chance of causing a pregnancy. Also you are assuming an unconditional probability. It could very well be a conditional probability. It might completely work for 99% that do not cause any pregnancies at all and not work for 1% that cause pregnancies as without the drug.
Anyway I am looking forward to getting the perl index for humans from clinical trials.
Edit: fixed wrong wording