View Full Version : probability,variance,moment generating function


thandu3
03-01-2009, 11:10 AM
1. Let X denote the mean of a random sample of size 75 from the distribution that has the pdf f (x)=1, 0 <=x<=1. Calculate P (0.45 <X< 0.55).
2. Derive the moment-generating function for the normal density.
3. Let Y n (or Y for simplicity) be b (n, p). Thus, Y / n is approximately N [p, p (1 -p) / n]. Statisticians often look for functions of statistics whose variances do not depend upon the parameter. Can you find a function, say u(Y / n), whose variance is essentially free of p?

Masteras
03-01-2009, 12:58 PM
a) 0.55-0.45
b) integral from -inf to +inf of exp(tx)*f(x)dx
where f(x) is the formula of the normal
c) normal distribution?