Im almost positive this is it... Ok so if this test detects PEDs 88% of the time and is rite 94% of the time and we have 1000 players to test 25% of which actually do take PEDs, and we want to answer for A we need to find how many tested positive. To find that we need to do 1000* .88 = 880. So 880 people are tested positive.Only 94% and 6% is wrong so we do 880*.6= 528 people to find how many people were wrongly accused. (notice we didn't multiply 880 by the amount of people who actually do PEDs because the test will not always determine those who actually do it as positive) theamount of people wrongly accused out of 1000 is 528.
Now we need to find how many people who actually use PED's and aren't accused. To do this we need to find how many people actually do it. So 1000*.25= 250 people. So now we know 250 people do PED's. 88% of people are detected, so we want to know how many arent detected. So 100-88= 12% not detected. So 250 * .12= 30. So 30 people are not detected.That's the part I'm unsure of (part B i mean)The other way i was thinking of would be to do 1000* .88=880 so 880 are detected and 1000-880= 120. So 120 people are not detected. So we now do 120 * .25= 30 people not detected. YOu get the same answer i just don't know which is technically correct
