Which of the following statements about probability is most accurate?
　　A. A conditional probability is the probability that two or more events will happen concurrently.
　　B. An outcome is the calculated probability of an event.
　　C. An event is a set of one or more possible values of a random variable.
　　D. Out of a sample of 100 widgets 10 were found to be defective, 20 were perfect, and 70 were OK. The probability of picking a perfect widget at random is 29%.
　　Answer:C
　　Conditional probability is the probability of one event happening given that another event has happened. An outcome is the numerical result associated with a random variable. The probability of picking a perfect widget is 20 / 100 = 0.20 or 20%.