You have a task of identifying alligators and crocodiles based on their respective lengths. The average length of an adult crocodile is about 15 feet, while the average length of an adult alligator is 12 feet. Assume their length x follows a Gaussian distribution with a standard deviation of 2 feet. Assume their prior probabilities are also the same. Where would you place a decision boundary to separate alligators and crocodiles (that is at what point between the two means 12 and 15 feet)?