Bad Fold? I Think So

First post, relatively novice player, so bear with me please. Trying to see if my math is right here.

I'm holding K [img]/images/graemlins/heart.gif[/img]9 [img]/images/graemlins/heart.gif[/img]

The board is 6 [img]/images/graemlins/heart.gif[/img] 8 [img]/images/graemlins/club.gif[/img] K [img]/images/graemlins/spade.gif[/img] 10 [img]/images/graemlins/heart.gif[/img]

The pot is $7.60, and the only other player in the pot opens for $4.75 after the turn. I mull it over and then fold, but I'm thinking after the fact that I could justify a call here mathematically. Here's where I want to check if my approach is correct.

Assuming I'm beat by a pair at the time, maybe even two pair, I have 12 outs (9 hearts and 3 other 7s). So I figure I have a 26% chance of drawing out here (12 outs out of 46 unknown cards).

My pot odds I calculate as follows: I'm being asked to call for $4.75 to win $12.35 (the $7.60 in there plus his $4.75 bet), so I'm getting 2.6 to 1. I think this means that I have to be a 27.7% dog or better to call (i.e., 1/(1+2.6) ), but this I'm not certain of.

So if this analysis is correct, it's close to a push - I'm a 26% dog and I need to be at 27.7% to call, and given that if I hit I'm gonna' get a little more out of him on the river, this pushes me over the top and makes it a good call. So in retrospect I think I was wrong to fold here.

I'm probably oversimplifying here (e.g., ignoring the possibility that my third heart gives him a boat), but just wanted some feedback as to whether my mathematical approach is correct.

As I write this, I realize that I've ignored the possibility that he already has a made straight, which is perhaps a bigger oversight.

Apologies in advance if this belongs in the newbie forum, and thanks.