Official ECMT 1010 thread. (1 Viewer)

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from the word document, 'Joint_Distribution', pg. 12, Week 5 Lecture Notes.
 

jpr333

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I'm pretty sure that's standard deviation of x * standard deviation of y
 

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jpr333 said:
I'm pretty sure that's standard deviation of x * standard deviation of y
that's what i assumed, so i tried finding Sx and Sy thru Std Dev but the value is completely off to what they got.... help :(
 

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Checking my notes it is SD, just make sure you root the answer cause the equation E(X^2) - [E(X)]^2 is = variance or standard deviation^2.
 

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jpr333 said:
Checking my notes it is SD, just make sure you root the answer cause the equation E(X^2) - [E(X)]^2 is = variance or standard deviation^2.
ok thanks for that... i'll try it again but later in the day... right now I'm preparing for the second econ quiz... woopeedoo
 

s.m.i.t.h

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when are the goddam notes for this weeks ecmt lectures gonna be put up?
 

absolution*

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Does anyone have the notes for CLT. I have no idea what it is because i didnt go to the lecture and its not in the textbook. Help me.
Please.
 

absolution*

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ToO LaZy ^* said:
prepared to get bombed with fetish pRonz. :D
Dude, what else would you assume my inbox to full of already? There aint nothing hotter than midget-interracial-huge boobs-albino-milf pr0nz.
 

absolution*

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thanks big boy

i have a qu.

With say... Var(4X-Y+3)

where varx=4 and vary=5 covxy=12

it would be 16(16) + (1)(25) + 12(4)(-1) = etc...

why is it that the varx and vary are squared?

according to the formula id assume it should be:

16(4) + (-1)(5) + 12(4)(-1) = etc... as you dont square the varx and vary's.
 

absolution*

ymyum
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heh, i suck at maths

but in the quiz 2 example you and lainee were squaring the varx and vary???
 

absolution*

ymyum
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right so if you get stdev symbol (subscript) x that needs to be squared when you use it in that equation?
 

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