Question

A blood test to detect prostate cancer in men gives a positive result 96% of the time if a person has prostate cancer, and it is 97% accurate for people who do not have the disease. What is the probability of getting a false positive result (that is, a person tests positive but does not actually have the ailment)?
A.0.01
B.0.03
C.0.04
D.0.07
E.0.97

Answer 1

@amistre64

Answer 2

if 97% is accurate then 3% could be the possible mistake

Answer 3

@whpalmer4

Answer 4

@ganeshie8

Answer 5

idk that sounds reasonable but its not an answer choice

Answer 6

yes it is, 3% equals to .03

Answer 7

to convert percent to decimal you just move the point twice to the left

Answer 8

ohh, i never knew that..

Answer 9

\[n\% = \frac{n}{100}\]

Answer 10

and to convert decimal to percent just move the point twice to the right example
0.97 = 97%

Answer 11

what is n?

Answer 12

n is just a variable for any percent amount, for example
n% = n/100

97% = 97/100

Answer 13

idk are you sure its .03?

Answer 14

why are you not sure, what is it that you don't understand

Answer 15

why isnt it .04?

Answer 16

because the question ask for the people that does NOT have the disease and get positive result, therefore you are working with the 97%

Answer 17

alright ill go with .03

Answer 18

now if the question was what is the probability of a person having the disease and getting a not accurate result then you work with the 96%

Answer 19

how many people do not have the ailment?

Answer 20

what?

Answer 21

97% accurate for people who do not have the disease. would indicate that its 3% false positive

Answer 22

yea and then ivette said you move the decimal to the left twicce which gives me .03

Answer 23

ivette was correct ... see, there are others :)

Answer 24

yea i guesss..