*Help me pass my Probability test tomorrow*
Sorry to start an uninteresting thread, but I have a test at 9:45 tomorrow and I have no idea how to do either of these problems, so any help would be greatly appreciated.
1. Let f(x) = a/(x(x+1)(x+2)), x = 1,2,3,...
a. Find a.
b. Find E(x)
c. Find Var(x)
2. X ~ Binomial (n=24, p=0.2). Use binomial theorem to find
a. E(0.7^x)
b. E(0.8^x)
If you can just give me the general gist of how to do these, you'll be my hero.
Also, if anybody knows a good forum where I could post questions like this instead of here, that would be great too.
|