5. Describe the parameters of interest in words. (You can use the symbol a to represent these parameters.) 6. State the null and alternative hypotheses for a test of significance to see whether this experiment pro- vides statistically significant evidence that Vitamin C prevented colds in the skiers. Use a one-sided test. 7. Of the 139 skiers assigned to take Vitamin C, 17 developed a cold. Of the 140 skiers assigned to take a placebo, 31 developed a cold. Fill in the 2 x 2 table provided. Vitamin C Placebo Total No cold Cold Total 8. Incidence is the term used to describe the percentage of the sample who onset with an illness over a certain time period. In this case, the incidence rates are the same as the conditional proportions. Find the incidence rates for individuals who received Vitamin C and those who received the placebo. To enter special characters and formatting. use "Cul+E" in Windows and "Cid + E" in Mac. STEP 3: Explore the data. 9. What is the difference in incidence rates in the two groups? Before doing a test of significance, com- ment on whether you think this is evidence that Vitamin C prevents colds. STEP 4: Draw inferences beyond the data. Let's use our 3S strategy to help us investigate how much evidence the sample data provide to support our conjecture that Vitamin C prevents colds. 10. What is the statistic that you can use to summarize the data collected in the study? 11. Use the Two Proportions applet to carry out a test of significance