Good at Stats? earn 50mill credits!

[Divine Intervention]

okay im having a stats exam soon and i absolutly hate stats. ive been getting worse marks in it compared to my other exams all the way from GCSEs to Uni level. anyway can anyone help me with these Covarience questions?

i know how to do E(X), E(Y), the varience questions and Cov(X,Y) but the following have me very confused:



for the first one i need to find Cov(Y,Ysquared) ie Cov(Y,Y^2)

for the second one i need to find Cov(X,Y|x>=14) ie Cov(X,Y given that x is greater or equal to 14).

i have the answers but dont understand how they were obtained. help appreciated and rewarded.

i hate statistics

EDIT: i worked out how to do Cov(Y,Y^2) --> E(Y^3)-E(Y)E(Y^2) --> 28.7 - (8.9*2.7)=2.89. so i only need help with the second one now please

EDIT: can mod change title to 50mill please considering ive done half the work already although worry not mathematicians, im sure to have plenty more questions and will be giving generous rewards for help

[Crimson Shadow]

If only I knew stats I would help you out.

Title changed.

[Divine Intervention]

thanks crimson guess no one will get any cash, my friend from Oxford helped me out. conditional probability its called

doing Cov(X,Y) as normal but ignoring the X=13 column and having the probabilities u do use divided by the sum total of them (so p(x=14 is .1/.7). god i hate stats.

[Disorder]

Sorry.. my wife and I looked at it and can't help.

[L P]

The answer is 42.

Now give me my credits, I'm broke.

[Bram Gotink]

The answer is 42.

Now give me my credits, I'm broke.

[nosejam]

Weirdly enough I got both my highest and lowest marks in Stats, S1 I got 99% in, S2 I'm not sure what I got, but sub-50% I imagine.

That was a good two/three years ago and I can't really remember anything, just some very basic stuff that applies to quantum physics, which just involves normalising some wave functions and getting expectation values.

[Divine Intervention]

well doesnt matter any more, had my stats exam, think it went fine
*fingers crossed*

[FeaRLezZoN3]

Man i am soo happy I didnt go to college....I have no clue wtf those numbers and x's mean

[nosejam]

Man i am soo happy I didnt go to college....I have no clue wtf those numbers and x's mean

Could've done Geography, the only entrance requirement is you have to be able to stay within the lines when colouring in.