20. By definition, jumbo shrimp are those that require between 10 and 15 shrimp to make a pound. Suppose that the number of jumbo shrimp in a 1-pound bag av- erages u = 12.5 with a standard deviation of o = 1.5, and forms a normal distribution. What is the probabil- ity of randomly picking a sample of n = 25 1-pound bags that average more than M = 13 shrimp per bag