1. A manager at the Reno VA hospital records the following table regarding patients seen on a given day with respect to blood type.

Totals	Blood Type	Total
A	B	AB	O
560	770	1,253	2,476	5,059

1. What is the probability of a patient having blood type O on this given day? (2 points)
2. What is the probability of a patient having blood type AB or A on this given day? (2 points)
3. Suppose a new surgical intern operates on eight patients using a procedure that has a current estimated success rate of 76%. The following table illustrates the total number of possible successes for the intern and their corresponding probabilities:

Probability	Number of Successes
0	1	2	3	4	5	6	7	8
0.001	0.011	0.072	0.103	0.127	0.173	0.278	0.146	0.080

1. What is the expected number of successful operations for the surgical intern? (2 points)
2. What is the variance of the distribution? (2 points)
3. The following is a table relating a group of 1000 patients' true breast cancer statuses and their corresponding test results after receiving a mammogram.

Cancer Status	Test Result Positive	Test Result Negative	Total
Breast Cancer	223	80	303
No Breast Cancer	13	684	697
Total	236	764	1000

1. What is the probability of a positive test, given that the patient has breast cancer? (2 points)
2. What is the formal term used to describe this probability measure? (2 point)
3. What is the probability of a negative test, given that the patient is breast cancer free? (2 points)
4. What is the formal term used to describe this probability measure? (2 point)

1. A research group is interested in the relationship between exposure to mold in households after a major hurricane and the onset of acute respiratory illness (ARI) in children. Suppose an observational study was conducted over 10 years following the natural disaster, and the following two-by-two table was created to address the relationship between the exposure and outcome.
   1. Calculate the incidence of ARI in the exposed and unexposed. (2 points)

	Acute Respiratory Illness	No Acute Respiratory Illness	Total
Mold	378	156	534
No mold	73	260	333
Total	451	416	867

1. Calculate the relative risk for ARI due to exposure in this study. (2 points)
2. Interpret the results you calculated in part b. (2 points)