III Problem Solving

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ProblemSolvingAssignment3.docx

PUH 5302, Applied Biostatistics

Unit III Problem Solving Assignment

This assignment will allow you to demonstrate the following objectives:

· 4.1 Compute and interpret probability for biostatistical analysis.

· 4.2 Draw conclusions about public health problems based on biostatistical methods.

Instructions: In this assignment, you will be applying the concepts of probability that you have learned in this unit. To complete this assignment, answer the questions directly on this document. You may use as much space as you need to answer the questions. When you are finished, select “Save As,” and save the document using this format: Student ID_Unit# (ex. 1234567_UnitI). Upload this document to Blackboard as a .doc, docx, or .rtf file.

1. Calculate the sample size of an unknown population with the given information. Use the appropriate formula discussed in the unit lesson. Show your work.

a. 90 % z-score = 1.645

b. Margin of error = (+/- 5%)

c. Standard deviation .5

d. 90% confidence level

2. Examine the following table carefully:

Screening

Disease

No Disease

Total

Positive

A = 10

B = 20

A + B = 30

Negative

C = 2

D = 30

C + D = 32

Total

A + C = 12

B + D = 50

N = 62

Calculate the following variables by using the appropriate formulas given in the unit lesson.

a. Prevalence

b. Sensitivity

c. Specificity

d. Positive predictive value

e. Negative predictive value

Please interpret your results. How could these results be used to target or treat the disease in a given population?

3. First, define the following terms:

a. Sensitivity

b. Specificity

c. Positive predictive value

d. Negative predictive value

For the screening test for Down Syndrome the following results were obtained:

Screening Test Result

Affected Fetus

Unaffected Fetus

Total

Positive

10

300

310

Negative

2

4,442

4,444

 Total

12

4,742

4,754

Based on the data above, calculate the following:

a. Sensitivity 

b. Specificity 

c. Positive predictive value

d. Negative predictive value

Please interpret your results. What do these results tell you about Down Syndrome in this population? Could any conclusions be drawn from this data?