Mathematical proofs

1. Proof by example. 
"I know Asians that are good at math, therefore all Asians are good at math."  Q.E.D.

2. Proof by intimidation (argumentum verbosium).  If something is told loudly/with the right angry intonation, you will start believing that it's true.  Statistically, this method is used by women 84.7% of the time.
Ex: "It's ok if you think I look fat, just tell me, I won't get mad"
Note: Studies show that most statistics are meaningless nonsense.

3. Proof by superiority.   "I went to Wharton/Harvard/Goldman, so my answer is correct and yours is wrong"

4. Proof by authority (argumentum ab auctoritate).  Similar to above, but using fictitious figures of authority, instead of your own lackluster credentials, to justify your argument.
"Respected people from Wharton/Harvard/Goldman agree with me that ..."