YES!!! I GOT 28%!!! HA HA HA!! Oh wait, I'm screwed. Darn.
I got a 67% chance, but I'm adding 5 percentage points because I'm going to trip Sarah to give me a bigger running gap when the zombies stop to eat her tasty, tasty brains.
What? Like you wouldn't do it? She's got less than a 50% chance of surviving, people! Since she's a gonner anyway, her death might as well be meaningful by giving me that much more chance to live.
And, Sarah? I totally want to thank you in advance for your sacrifice. It's a shame to lose selfless person like yourself, but we know you do it for the greater good. Or I do it to you for my own good. Either way works for me.