Blind test video - PCM, FLAC, mp3 vbr, mp3 320 kbps
Dec 19, 2009 at 11:37 PM Thread Starter Post #1 of 4

Patrick82

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I had 4 options to choose from and scored 4/4 which is 1 chance in 256. Then I got fatigued and dropped to 5/6, then 7/9. I'm in the process of learning how to calculate the odds with math (permutations and combinations), I know how to calculate when there are 2 options, but now there are 4, how do I calculate this?

Is this video statistically significant?
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.

 
Dec 20, 2009 at 1:16 AM Post #2 of 4

westies

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What's the point of this? 2 of your options are identical and the two mp3 choices say nothing about the encoder or options used. "VBR" tells you nothing.

..
lol, nevermind. Reading your thread on Ubuntu vs XP and watching that video pretty much confirms that you're trolling.
 
Dec 20, 2009 at 1:44 AM Post #3 of 4

Patrick82

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Quote:

Originally Posted by westies /img/forum/go_quote.gif
What's the point of this? 2 of your options are identical and the two mp3 choices say nothing about the encoder or options used. "VBR" tells you nothing.

..
lol, nevermind. Reading your thread on Ubuntu vs XP and watching that video pretty much confirms that you're trolling.



The point was to prove with a blind test video that I'm not trolling. PCM and FLAC are not identical because FLAC uses 1% CPU power while PCM uses 0%. I used the default VBR values, I don't know what it is, but it sounds different than 320 cbr.
 
Dec 20, 2009 at 4:40 PM Post #4 of 4

Patrick82

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I calculated the possibilities manually at first, it took a very long time, but after many hours I figured it out. Is this how to do it?

5/6
First calculate all possibilities (4 options, 6 trials): 4^6 = 4096
Then calculate combinatorial: 5/1 = 5
Then calculate how many ways to answer 1 wrong = 3^1 = 3
Then multiply them: 5*3 = 15 (there are 15 possibilities to answer 5/6 correct)
Then divide with all possibilities with that number: 4096 / 15 = 273

Add possibility of answering 6/6 (+1 possibility): 4096/16 = 256

It is 1 chance in 256 to answer at least 5 correct of 6 trials.


7/9
Possibilities: 4^9 = 262144
Combinatorial: (9*8) / 2 = 32
Answer wrong: 3^2 = 9
Multiply: 32*9 = 288
Divide: 262144/288 = 910

Add 8/9: (9/1)*(3^1) = 27
Add 9/9: 1
288 + 27 + 1 = 316
Divide: 262144/316 = 829.57

1 chance in 830 to answer at least 7 correct of 9 trials.


7/11
Possibilities: 4^11 = 4194304
Combinatorial: 11*10*9*8 / 4*3*2*1 = 330
Answer wrong: 3^4 = 81
Multiply: 330*81 = 26730
Divide: 4194304/26730 = 156.9

Add 8/11: ((11*10*9) / (3*2*1)) * (3^3) = 4455
Add 9/11: ((11*10) / (2*1)) * (3^2) = 495
Add 10/11: (11/1) * (3^1) = 33
Add 11/11: 1
26730 + 4455 + 495 + 33 + 1 = 31714
Divide: 4194304/31714 = 132.25

1 chance in 132 to answer at least 7 correct of 11 trials.
 

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