Suppose that sodium pentobarbital is used to anesthetize a dog. the dog is anesthetized when its bloodstream contains at least 45 mg of sodium pentobarbitol per kilogram of the dog's body weight. Suppose also that sodium pentobarbitol is eliminated exponetially for the dogs bloodstream, with a half-life of 5 h. what single dose should be administered in order to anesthetize a 50-kg dog for 1 h?