[C3] An oil company conducts a geological study that indicates that an exploratory oil well should have a 30% chance of striking oil. What is the mean and variance of the number of wells that must be drilled if the oil company wants to set up three producing wells? (Hint. Find the mean and variance for a negative binomial random variable). 4.2857 and 1.8367 = 10 and 7.7778 = 10 and 23.3333 = 7 and = 36