Drug testing Lets say the following conditions are true 1 Th

Drug testing.

Let\'s say the following conditions are true:

1. The drug test is 96% accurate.

2. The population being tested is known to have 10% drug users.

Let\'s consider 1000 people being tested (no commas in the numbers please).

Fill in the following table and then answer the two questions about probability.

Drug testing. Lets say the following conditions are true 1. The drug test is 96% accurate 2. The population being tested is known to have 10% drug users. Lets consider 1000 people being tested (no commas in the numbers please) Fill in the following table and then answer the two questions about probability. Row Totals Positive Test Negative Test Drug 100 P(Non Drug User I Tested Positive) = Write answer as a decimal rounded to three decimal places. (This would be the probability of an innocent person being falsely accused or a false positive.) Non-Drug P(Drug User | Tested Negative) Write answer as a decimal rounded to three decimal places. (This would be the probability of a guilty person not being accused or a false negative.) to three decimal places 1000

Solution

a)

P(non drug user / tested positive) = 36/132 =0.27

b)

P(drug user / tested negative) = 4/868 = 0.0046

	positive test	negative test	row totals
drug users	96	4	100
non drug users	36	864	900
column totals	132	868	1000