PUBH 6033—Week 5 Assignment:

Steps to Hypotheses Testing

(Rubric included)

 Instructions

For this Assignment, review this week’s Learning Resources, including the 5 step approach to hypothesis testing document. Read the research scenario, below, and then answer the questions related to the steps that must be followed to make the appropriate decision as to reject or fail to reject the null hypothesis.

Submit this Application Assignment by Day 7.

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Research Scenario

IQ scores from the general population form a normal distribution with a m = 100 and s = 15.  However, data indicate that children’s intelligence may be affected by early exposure to lead.  Using hospital records, a researcher obtained a sample of n = 121 children who had lead exposure.  The average IQ for this sample was x̅ = 96.  Do these data indicate that exposure to lead has a significant effect on IQ?  Test with p=.05.

Note

µ = population mean

x̅ = sample mean

s = standard deviation

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Note: Each response is worth 6 points

Step 1: Set up your hypothesis and determine the level of significance

State the null hypothesis

1. In written format

Answer:

2. In mathematical format  

Answer:

State the alternative hypothesis

3. In written format 

Answer:

-Continued below-

4. In mathematical format  

Answer:

Determine the Level of significance

5. Based on information in the scenario, what is the level of significance to be used?

Answer:

Step 2: Select the appropriate test statistic

6. The appropriate test statistic for the above scenario is the one-sample z test. What is a Z test?  Describe why this is the appropriate test for the scenario?

Answer:

Step 3: Set up the decision rule

7. Based on the level of significance you set in Step 1 (Question 5) and whether your alternative hypothesis is directional or non-directional, what is your decision rule? (In other words, what is your rejection region?)

Answer:

Step 4: Compute the test statistic

8. Calculate the z statistic.  Please show your work.

Answer:

Step 5: Conclusion

9. Do you reject or fail to reject the null hypothesis?  

Answer:

10. Is a child’s intelligence affected by lead exposure?

Answer:

Section below (scoring) is to be completed by Instructor

Scoring Rubric for Week 5 Assignment1.v1—Hypothesis Testing (60 points)

Initial Score (60 possible points):          

Timeliness Factor (late points deducted):        

Total Score (60 possible points):         

Instructor comments: