You just got a new puppy, and you need to determine the best way to have him cared for while you are at work. You could enroll your puppy in a doggy daycare in your neighborhood for $22 per day. Alternatively, your friend, who works from home, could care for your puppy for only $10 per day. However, your friend lives a few miles away, so it would cost you $6 per day in gas and $10 per day in time to drop your puppy off and pick him up. If you choose to take your puppy to daycare, are you correctly applying the cost-benefit principle? Explain.