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Post by ITFC Dudette6 on Mar 22, 2007 14:38:09 GMT -1
Sure it's nothing to do with Mongeese? GB, everything has to do with mongeese! ;d
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Post by Pete the Wolf on Mar 22, 2007 16:28:50 GMT -1
Mate, you've already divided by the sample size in the standard deviation. The variance is just (standard deviation)², so no, you don't need to divide. What's the numbers you've got anyway, and what've you got to calculate. (yes I'm bored and looking for something to do along with one of my assignments, so I'd happily do some stats as well )
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Post by Tony Yeboah's Lunchbox on Mar 22, 2007 16:37:29 GMT -1
Can anyone tell me whether i have to divide ó 2 by my sample population (n), or whether i leave it, to get the sample variance. Thanks in advance! Yeah...um....hmm....err..... Ask Pete The Wolf
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Post by Tony Yeboah's Lunchbox on Mar 22, 2007 16:38:00 GMT -1
Haha trust Pete, already had answered!
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Post by Pete the Wolf on Mar 22, 2007 16:53:41 GMT -1
Haha trust Pete, already had answered! ;D
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Post by Rulesaints on Mar 22, 2007 17:02:27 GMT -1
yer all you need to do is square the s.d.
(I think)
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Post by Alex on Mar 22, 2007 21:40:41 GMT -1
Mate, you've already divided by the sample size in the standard deviation. The variance is just (standard deviation)², so no, you don't need to divide. What's the numbers you've got anyway, and what've you got to calculate. (yes I'm bored and looking for something to do along with one of my assignments, so I'd happily do some stats as well ) Well, i have got completely fucked up answers! I'm going to have start it all again! I've got maths tomorrow so i'll ask my teacher. Cheers anyway though Petey!
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Post by Tony Yeboah's Lunchbox on Mar 22, 2007 22:06:13 GMT -1
Pete is the next Albert Einstein.....
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Post by Pete the Wolf on Mar 22, 2007 22:22:29 GMT -1
Mate, you've already divided by the sample size in the standard deviation. The variance is just (standard deviation)², so no, you don't need to divide. What's the numbers you've got anyway, and what've you got to calculate. (yes I'm bored and looking for something to do along with one of my assignments, so I'd happily do some stats as well ) Well, i have got completely fucked up answers! I'm going to have start it all again! I've got maths tomorrow so i'll ask my teacher. Cheers anyway though Petey! No problem mate In the meantime, perhaps people would care to look at my Intrumentation systems assignment 1a. Calculate the tms noise voltage and current of a 1 MÙ resistor operating into a bandwidth of 1 kHz at 300K b. Convert the following into decibels (dB) (i). a power gain of 10 (ii). a voltage gain of 1 (iii). a power gain of 0.5 (iv). a voltage gain of 10 62. An amplifier has an open-circuit voltage gain of 20, an input resistance of 10 kÙ and an output resitance of 75Ù. The input to the amplifier is an a.c. source of 1V rms and output resistance of 200Ù, and there is a load resistance on the output of the amplifier of 1 kÙ. Determine the rms value of the voltage across the load. 3. A photomultiplier has a gain of 10 6, a quantum efficiency of 10%, a dark current of 10 -14A and a bandwidth of 10 MHz. It is irradiated with light of wavelenth 600 nm. If the anode load is 1 MÙ with a stray shunt capacitance of 5 pF, calculate the minimum optical power that can be detected by the photomultiplier. (Ignore dynode noise). Just the final one I need to do, have been sifting through my lecturer's ntoes searching for the formulae needed.
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Post by Pete the Wolf on Mar 23, 2007 13:53:23 GMT -1
p.s. Don't worry I wasn't seriously asking for help. If anything, I'd be in trouble for unfair practice anyway, was just putting those questions up to show my next assignment due.
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Post by Neko Bazu on Mar 23, 2007 13:56:15 GMT -1
Two years ago, I could've done those. I'm way out of practice now though, and don't have my formula sheets anyway!
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Post by Pete the Wolf on Mar 25, 2007 22:54:23 GMT -1
Pete is the next Albert Einstein..... Just noticed this comment! I think that's a BIT to far mate! Maybe Planck or Boltzmann and then I can have a constant named after me.
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