Which of the following is a discrete numerical variable? a. The volume of water released from a dam b. The distance you drove yesterday c. The Dow Jones Industrial average d.The number of employees of an insurance company The number of power outages at a nuclear power plant has a Poisson distribution with a mean of 6 outages per year. What is the probability that there will be exactly 3 power outages in a year? a. 0.8920 b.0.0108 C. 0.0892 d.0.1020 The universe or "totality of items or things" under consideration is called a. a population b. a sample c. a statistic d. a parameter