Side effects present

Side effects absent

Screen positive

12

4

Screen negative

80

234

1.The following table shows the results of a screening test hypothesized to detect persons at risk for side effects of a new cosmetic surgery. Compute the specificity of the test.

2.A clinical trial designed to show the efficacy of a new drug in reducing progression to hypertension reports the following data. Using this information, compute the relative risk of progression to hypertension among patients receiving the new drug as compared to the placebo.

New Drug

Placebo

Sample size

200

200

Progression to hypertension

11%

21%

No Disease

Disease

Screen Negative

1351

20

Screen Positive

39

41

3.The following table shows the results of a screening test hypothesized to identify persons at risk for a rare blood disease. Compute the False Positive Fraction of the test.

4.An experimental drug has been shown to be 80% effective in eliminating symptoms of allergies in animal studies. A small human study involving eight participants is conducted. What is the probability that the drug is effective on half of the participants?

5.Four hundred melanoma patients were diagnosed according to the type of skin cancer and the location of the skin cancer. This data is presented below. What proportion of patients had Hutchinson's melanomic freckle?

Location

Type

Head and Neck

Trunk

Extremities

Total

Hutchinson's melanomic freckle

22

2

10

34

Indeterminate

11

17

28

56

Nodular

19

33

73

125

Superficial spreading melanoma

16

54

115

185

Total

68

106

226

400

6.The gestation period for human births can be taken as normally distributed with a mean of 256 days and a standard deviation of 16 days. If a gestation period is 276 days, what percentile among human births is this?