I don't agree that the decision is about pot odds.
That would apply in a cash game of course but, at this stage of the MTT, your decision is more complex. Pot odds are part of the equation of course, but you should really be considering your tournament equity- especially as the all-in is coming from the player who has you covered. Therefore the payout structure is important too.
If the top 3 places paid, say, $1000, $600, and $400.
Then if you folded, the chip count and tournment equity (calculated from this website:
http://www.reviewpokerrooms.com/poker-games/general/tournament-equity.html) would be as follows:
CL: 150k ($778)
Hero: 110k ($729)
Other: 40k ($493)
If you called and lost, your equity (3rd place prize) is $400
If you called and won, the chip count/equity would be:
Hero: 250k ($931)
Other: 40k ($614)
Ex-CL: 10k ($454)
So, calling and losing costs you $329, whilst calling and hitting wins you $202, so you would need to be a 62% favourite to make calling the correct decision.**
Technically, it's a little more complex than this. You would really need to take into account the ability of each player, the action of the short stack to act after you (we are presuming that he will fold here), size of blinds, even button position (if blinds were significantly large.) E.g. If you considered yourself a far better players than the other two, then you would have to increase the "favourite percentage" from 62% by some subjective amount (and decrease it if you felt the other players were better than you.)
Of course, you wouldn't have time to make as precise a calculation as above within your time period, but I'm sure it becomes a pretty instinctive decision to experienced tournament players.
**Contrast this with the identical position in a cash game: You have to put in $110k to win $150k, so you only need a 44% chance of winning the pot. It's easy to see from this significant difference in percentages just how different (and how much easier) a decision you have at the cash table.