Respuesta :
Answer:
Step-by-step explanation:
Given that a new drug test needs to be evaluated. The probability of a random person taking drugs is 4%.
The drug test tested positive for a person not taking drugs 2% of the time. The drug test tested negative for a person taking drugs 1% of the time.
Tested positive Tested negative Total
Having drug 0.98 0.02 1.00
not hav drug 0.01 0.99 1.00
a) the probability that a random person tests negative
= Prob ( really negative and test negative) + Prob (positive and test negative)
[tex]= 0.96*0.99+0.04*0.02= 0.9504+0.0008=0.9512[/tex]
b) the probability that a person who tests negative is without any drug problems
= [tex]\frac{0.9504}{0.9504+0.0008} \\=0.9992[/tex]
