This table is repeated from the previous page. No values have been changed.

(e)	Has Disease (Infected)	Does Not Have Disease (Healthy)	Totals
Positive	True Positive ___12125________	False Positive ___1875________	_____14000______
Negative	False Negative ____375_______	True Negative ___35625_______	_____36000_____
Totals	____12500_______	___37500______	50,000

Answer as a percentage rounded to two decimal places. Show your calculations.

1. What is the probability that someone in this population has the disease or tests positive? (4 pts)

1. What is the probability that someone in this population receives a false test result? (4 pts)

1. If a person has a positive test result, what is the probability that they have the disease? This is the positive predictive value. (4 pts)

1. If a person has a positive test result, what is the probability that they do not have the disease? This is the false discovery rate. (4 pts)

1. If a person has a negative test result, what is the probability that they do not have the disease? This is the negative predictive value. (4 pts)

1. If a person has a negative test result, what is the probability that they do have the disease? This is the false omission rate. (4 pts)

Recall that the new test has sensitivity of 97% and a specificity of 95% making it a reasonably accurate test.

1. The new test was used in several other populations with varying disease prevalence. The table below shows those results. The population that you examined on p. 5-6 has not been filled in yet. Copy your answers from p. 5-6 questions 13, 17, 18, 19, and 20, into the correspondingly numbered cells of the table. (1 pt)

Prevalence	Positive Predictive Value	False Discovery Rate	Negative Predictive Value	False Omission Rate
2%	28.36%	71.64%	99.94%	0.06%
13.		17.		18.		19.		20.
14%	75.95%	24.05%	99.49%	0.51%
50%	95.10%	4.90%	96.94%	3.06%

Answer the following questions in complete sentences. Mention specific column names and/or values to support yourconclusions.

1. As the disease prevalence in a population increases, does the false discovery rate increase or decrease? Explain. (2 pts)

1. Is a positive result more likely to be true when the prevalence is high or low? Explain. (3 pts)

1. When a disease is rare in the general population, doctors are not likely to test everyone. Instead, they only test people that have specific risk factors or show symptoms of the disease. Even if resources are available, why do you think doctors would avoid giving a test for a rare disease to everyone in the general population? Explain using ideas from probability that were explored in this project. (5 pts)

All the questions are based off of the columns provided