# BST 322 BST322 Week 3 Assignment (National University)

1.Using StatCrunch, calculate the chi-square statistic and degrees of freedom for the following set of data for 300 people:

Is the value of the chi-square statistically significant at the 0.05 level?

2.Write a paragraph summarizing the results of the analysis in Exercise 1.

3.Using StatCrunch, calculate the chi-square statistic and degrees of freedom for the following set of data for 180 people undergoing a knee replacement treatment with a drug supplement:

4.Write a paragraph summarizing the results of the analysis in Exercise 3.

5.Given each of the following circumstances, determine whether the calculated values of chi-square are statistically significant:

6.Match each of the nonparametric tests in Column A with its parametric counterpart in Column B

7.Using the information provided, indicate which statistical test you think should be used for each of the following situations:

8. The relationship between cigarette smoking and major depressive disorder has been studied for decades. In the doc sharing area of the course, you will find an excel spreadsheet of data from a study on smoking and depression by the St Louis Epidemiologic Catchment Area Survey of the National Institute of Mental Health. The file is labeled “Catchment Area Survey”. Using this data set in StatCrunch, calculate the chi-square statistic and degrees of freedom for the items “smoker” and a measure of depression, “FeltDown”. Construct a contingency table for this data as we did in week 1. Be sure to include and label the row, column and total %’s as well as the expected counts.

9. Write a paragraph summarizing the results of the analysis in Exercise 8. What can you conclude about smoking and depression (“Feeling Down”) in this sample?

10. Below are three (a-c) sets of cells of **2 X 2 **contingency tables including the **expected** frequencies (Totals not included). Identify which statistical procedure would be appropriate for each, using the most conservative approach.