1. Ethan is studying how many students use marijuana over a 30 day period. He tracks 10 students. Two smoke marijuana at the end of the first day. One smokes marijuana at the end of day 20. One leaves the study at the end of day 10. What is the incidence density rate? 2. In the year 2000, Springfield had a population of 200,000. 200 existing cases of colon cancer were reported. There were 25 deaths that were attributed to colon cancer. a. What measure would we use to estimate the proportion of colon cancers that are fatal? b. Calculate that measure: 3. Jana is studying the relationship between community violence and having at least one anxiety attack over a 2 month period. She follows 30 people for 2 months. Twenty people never have an anxiety attack. Five people have anxiety attacks at the end of the first month. Five people have anxiety attacks at the end of the second month. What is the total person-months accumulated in her study? 4. What is the incidence density rate? 5. Katrina is assigned to follow 15 students who are on academic probation for their duration at CSU East Bay. There is funding to determine whatproportion of students dropout who are on probation. Unfortunately, three students drop out before Katrina begins to follow the students. Three students drop right at the end of year 2. One student takes one year off from year 3 to year 4 but returns and graduates at the end of year 5, you can treat the year off as a temporary withdrawal. Two students transfers after one year - this is not considered dropping out. The remainder of students graduate at the end of year 5. How much person time is accumulated in this study?