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

                                                            Group A          Group B          Group C          Total

                        Had flu shot                     20                   30                    32                   82

                        Didn't have flu shot         80                   70                    68                 218

                        Total                               100                 100                  100                 300

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:

                                                Treatment with drug X    Treatment without Drug X     Total

Had > 8 wk rehab                   18                                32                                  50        

Had < 8 wk rehab                   70                                60                                  130

                        Total                88                                92                                 180

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

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:

a. χ² = 3.02, df = 1, α = 0.05

b. χ² = 8.09, df = 4, α = 0.05

c. χ² = 10.67, df = 3, α = 0.01

d. χ² = 9.88, df = 2, α = 0.01

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

            A. Nonparametric Test                        B.  Parametric Test

                  1.  Mann-Whitney U-test                    a.  Paired t-test

                  2.  Friedman test                                 b.  One-way ANOVA

                  3.  Kruskall-Wallis test                        c.  Independent groups t-test

                  4.  Wilcoxon signed-ranks test            d.  Repeated measures ANOVA

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

a. Independent variable: normal birth weight vs. low birth weight infants; dependent variable: 1 minute Apgar scores (1-10 scale).

b. Independent variable: time of measurement (before, during, and after surgery); dependent variable: heart rate.

c. Independent variable: time of measurement (before, during, and after intervention); dependent variable: did vs did not exercise regularly.

d. Independent variable: infertility treatment A vs infertility treatment B vs control condition; dependent variable: did vs did not become pregnant.

8. Below are three sets of expected frequencies for the four cells of 2 X 2 contingency tables. Identify which statistical procedure would be appropriate for each, using the most conservative approach.

            a.         4        4                        b.         35          35                  c.         9         9

                        21    21                                    65          65                            91       91