I actually would claim the opposite.

To say that 1 life is worth 5 is a brutal affront to humanity. Life should be equal.

As I said previously, no one life is any more or less than any one other life - even if you compare a sociopath to a scientist or great historical figure. They are both still equal.

The instant you have more than 1 life at risk for 1 life; the logical solution is to save as many as possible greater than 1.

Logic of course plays no part if you happen know any of the people; because there is no getting around the human factor that your family or friends are going to hold a higher value to you than random strangers. However, that still doesn't make the decision to save your wife and letting hundreds die (as an example) - the right decision. It does, though, make it an understandable one.

It would not be understandable to me if you were somehow in the position to save a hundred lives from a bomb or something else at great risk to a single someone else; and you just walked away deciding "not your business" because you didn't know anybody.. why should you care?

However, I wouldn't agree with anyone trying to say that you had a legal requirement to do anything.. I just personally think you should have a moral obligation too. *shrug*