4. In each of the following situations, (1) identify the most appropriate graph for summarizing the data, (2) identify a statistic (numerical summary) that could be used to describe the data, and (3) briefly provide a reason for your choice. [6 marks: 3+3] a. A sample of 250 young adults are taken and the amount of money each spent on celebrating Christmas is recorded. The distribution is highly right skewed. Graph: Statistic: Reason: b. A sample of 25 young adults are taken and the amount of money each spent on celebrating Christmas is recorded. The distribution is symmetric. Graph: Statistic: Reason: 5. Suppose we want our academic integrity sample to mirror the proportion of freshmen, sophomore, junior, and senior students in the overall college population and that we would like to select a sample size of 100 students. Freshmen, sophomores, junior and senior comprise 30%, 25%, 35% and 10% of the student population, respectively. a. Calculate the size of each stratum in our sample, based on its percentage relative to the population. [2] b. We can then apply the simple random or systematic sampling methods to select the students from each group. Why would we go through the trouble of using stratified sampling versus simple random or systematic sampling? [3]