Answer all below questions. Show your calculations, andwhereasked, explain your answers.

1. The probability of having condition A given someone already has condition B is 0.35. The prior probability of condition A is 0.4. The prior condition of condition B is 0.10. Using Bayes' Theorem, calculate the probability of having B given one has condition A. That is you are requested to calculate P(B|A).

2. A screening test applied to 1500 subjects identified 250 of them as positive. On further investigation, 110 of these were found to have the disease being tested for. In subsequent follow-up, 20 of the subjects who tested negative developed the disease within a reasonably short time.

• Calculate the sensitivity, specificity, and positive predictive value of the test.
• Explain in words what a test specificity of 75% means?
• Would you recommend using this screening test? Explain your answer.

3. Design an experiment or a survey and state howreliabilityof a component of your survey or experiment can be tested. Three aspects of reliability should be addressed:

• internal consistency
• stability
• interrater reliability

4. In a research project, the Cohen's Kappa that assessed interrater agreement was found to be 0.85. Explain in two or three sentences what this means.