Two separate after-school programs for at-risk teenagers have been implemented in the city of Redland. One is a big-brother/big-sister mentoring program, in which adult volunteers are paired with troubled teenagers. The second involves extracurricular team sports competitions. In terms of the percentage change in crimes reported to the police over a one-year period, were the programs successful? The results are for random samples of 18 neighborhoods drawn from the entire city. What is the unit of analysis (case?) Hint: in GSS 2018 the unit of analysis is a respondent. What is the total number of cases (n=?) How many variables are there in the problem? What is the unit of measurement of each variable? (year, mile etc.) What is the level of measurement of each variable? (nominal, ordinal or IR) What is the variable coding (for nominal and ordinal variables)