maggiemagnet wrote:If you're not sure what formula this is, try working backwards from the "sample" formulas they've given you. Which one uses in the numerator? Which one also uses in the denominator?
Martingale wrote:zorro wrote:Question :
Suppose X and Y are independent Poisson random variable , each with the mean 1 , obtain
Start with this...http://en.wikipedia.org/wiki/Poisson_distribution#Properties
stapel_eliz wrote:Assuming the decimal points stand for multiplication, could you please show the steps in your arithmetic with the fractions?
Martingale wrote:jk22 wrote:then p(knows|correct)=p(correct|knows)*p(knows)/p(correct)
That number seems a little low.
Martingale wrote:zorro wrote:Please can u tell what is wrong
My work ........
E(X) = 0
1 = 0
2 = 2/3
var(X) = 2 - 2 = 2/3 - 2/3 = 0
Martingale wrote:12 is not a probability