Stat 250 Fall 1998 Name ________________________________
Activity #4: Introduction to diagnostic testing Student ID __ __ __ - __ __ - __ __ __ __
Section #    1      2
 
You will be given 10 minutes to complete this activity.   Work on this activity with at least one other student.

A female student is interested in determining whether or not she should PANIC about the positive result she received when performing a home pregnancy test.  To answer her question, she finds the following data on the accuracy of the pregnancy test she used when performed on 1,000 college-aged women.
 
 

Test  Result
True Status Pregnant (+) Not Pregnant (-) Total
Pregnant (+) 48 2 50
Not Pregnant (-) 38 912 950
Total 86 914 1000
 

1.  What percentage of the women in the sample of 1,000 women were pregnant?
 
 
 

2.  What percentage of the women in the sample of 1,000 women tested positive?
 
 
 

3.  Given a woman is pregnant, what is the probability that she gets a positive pregnancy test?
 
 
 

4.  Given a women receives a positive pregnancy test, what is the probability that she is truly pregnant?
 
 
 

5.  Based on your above answers, argue one way or the other as to whether the student should or should not panic?  Can you recommend the next step she should take?