The Model a desert community where 60% is houses, 10%
is shops, and 30% is parks.
The area of the community that is houses is
represented by squares.
The area of the 10 munity that is shops is represented
by square
20
30
The area of the
by square
60
munity that is parks is represented

100,000 random people were tested for condition a. roberto's doctor told him he tested positive for condition a. if the test is 99% accurate and condition a is rare—one out of every thousand people have it. what is the probability that testing positive means roberto has condition a? 99.0% 1% 9% 99.9%