Recent content by JasonBrewer

Thanks haruspex for being patient and helping me out with the 2 questions. You've been a real help and I can't thank you enough for how helpful you have been. I hope you're around when I have more statistics related questions in the near future.

Is the general forula ((Z+1)/6)^4? E.g. suppose Z=3. What is the probability that none of the Y are <= 3? That is the probability P(X=0|Z=3). It would be a lot of work to write out all 25 combinations of P(X=x|Z=z), so see if you can work out the general formula. Since it would need to be...

Could you tell me a method that I can use without the hint? Althought the hint is helpful, I doubt that I will eb able to remember it. And yes I forgot to change the minus sign, I just copied and pasted it and just changed the denominators. E(Z/6-Z^2/36)=(1/5 * 1/6)+(2/5 * 1/6)+...+(5/5 * 1/6)-{...

Also would that mean that: E(Z/6-Z^2/36)=(1/5 * 1/6)+(2/5 * 1/6)+...+(5/5 * 1/6)+ [(1^2/36) *1/5]+[(2^2/36)*1/5] +[(3^2/36)*1/5]+...+[(6^2/36)*1/5] ?

Would you say that the method that you tried easier than the method given here by the hint?

Oh if you missed the answer on the previous page, it was 1.67 so you were right in thinking that it was less.

I wasn't sure how to work out a general formula for use with the hint, but if you got 48/25, I doubt that you're wrong, and suspect that the hint is incorrect-which is a bummer. How would you calculate the answer without the hint? The reason that I used this "Is the formula that I'm meant to...

Could you tell me if the answer that you got without/without the hint is 1.67?

Hint is derived from X|Z=z - B(4,(Z/5)) Var(X)=Var[E(X|Z)]+E[Var(X|Z)] so Var(X)=[4Z/5]+E[4(Z/5)(1-(Z/5))]

I have the answer to the question. Could you tell me the anser that you get. If you get different answers for the hint method and the method that you have chosen to do, I don't want to be doing something incorrectly.

Is the formula that I'm meant to be using nCr*p^r*(1-p)^(n-r)?

For 4E(Z/5 - Z^2/25) E(Z/5-Z^2/25)=(1/5 * 1/5)+(2/5 * 1/5)+...+(5/5 * 1/5)+ [(1^2/25) *1/5]+[(2^2/25)*1/5] +[(3^2/25)*1/5]+...+[(6^2/25)*1/5] Then multiply that above answer by 4. And this ans my post above, that would be the answer?

Ok so I'm not sure if this is correct, but I'll try and explain my logic behind this. So X is the number of Ys Less than or equal to Z. For Z=1, there is only one thing thess than or =to 1 (1/6) from Y, which is one. For 2, there are 2 things, 1 and also 2. so I get...

OH MY LORD. My friend gave me an answer to the wrong question! -0.073 was correct! I thought that I waas wrong the whole time. Thanks a bunch :D Var(X)=Var(4Z/5)+4E[z(1-(z/5))] For Var(4Z/5), you said that it doesn't scale linearly, and to use E(X) and E(X^2), but how do I apply either of...

Ok so i know I'm meant to use the formula Corr(X,Y)=E(XY)-E(X)E(Y) / sqrt[Var(X)Var(Y)] What I've got so far E(X)=0.05 E(X^2)=0.65 E(Y)=-0.05 E(Y^2)=-0.65 Var(X)=Var(Y)=0.6475 E(XY)=-0.05 When I put it into the formula, the answer the I get isn't correct. Is there something that I'm...