Your family/loved ones are tied onto a track. The incoming trolley's brakes have malfunctioned and cannot stop. If you had the knowledge that pushing a person into it's path would be enough to stop the trolley, would you push someone in?

You are placed in such a scenario. Would you push a random person in front of a trolley to save your loved ones? Instead of a stranger, what if it was your best friend? This is an isolated situation, which means it's only you, the stranger, and your loved ones. And the trolley. You cannot stop the trolley in any other way. Also, for whatever reason, sacrificing yourself won't work. You have to choose between killing this stranger or letting your family die. What will you do?