:) I'm glad that I can be of service! It was really odd that I had actually been reading a chapter of a book that discussed exactly this just the day before hence how I could remember the exact figures!
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man I thought I was good at math but this confused me!!! Lol i'm also 5'11 1/2 and weigh 152.8 pounds. So how tall/heavy should my horse be????

lol! Right to work it backwards (
may go wrong).
First of all conversion from pounds to kg (I prefer to work in kg):
152.8/2.2 = 69.5kg
I will now assume that your clothes, helmet and tack are 20.5kg ~ this is probably overestimating but it makes the maths easier!
Total weight therefore of 90kg.
Now it depends on what you do, for light work up to 30% is fine, heavy work is 20%. I shall therefore calculate 20, 25 and 30%!
For 20%  simply multiply 90 by 5 = 450kg horse*
25%  90 multiplied by 4 = 360kg horse/pony*
30%  (90 x 100)/30 = 300kg horse/pony*
* Min weight requirements for purpose.
To convert to height:
20%  As a general rule between 400500kg is the weight range for a 1415hh horse/pony. You would therefore be looking at 14' 2".
25%  Smaller!
30%  Even smaller!!
HOWEVER!!!! You say that you are 5' 11"; we'll call it 6'. While the above states how small a horse you can actually ride it does not give any info on how small a horse can be for you to look in proportion. The general rule is that you should stand a hand higher than your horse. Therefore if you convert 6 foot into inches you get 72. Take away 4 for the extra hand for 68 and then divide by 4 for conversion = 17hh!!
Conclusion  I would aim for a horse between 1517hh but if you want to compete seriously in dressage or showing then I would aim towards the top end. For normal purposes though you can actually technically ride a pony still without any real problems except of course your feet trailing the ground! However, you must also be careful not to over or under horse by just considering the height  both are important. For example, you get a few shires at 17hh; however, weight wise they are pushing a ton! They would clearly be too strong for you. You may also find one of the tb types who is around 16hh but is only just in your weight bracket on the lower scale.
Erg editing this like nothing on earth::: you must also beware of the top heavy horse who may weigh in well but have stick thin legs. There is a weight calculation that takes this into account but it is rather complicated to say the least and involves all these leg measurements etc. etc.