Bernoulli Trials Flashcards
1
Q
what are the two outcomes in bernoulli trials
A
success and failure
2
Q
how many outcomes can there be in bernoulli trials
A
2
3
Q
expected value in a bernoulli trial
A
E(X) = probability of success
4
Q
variance in a bernoulli trial
A
Var(X) = P success x P failure
5
Q
as the probability of success approaches 1 or 0 , how does variance change, why
A
variance gets much smaller
if you know that a success is very likely or very unlikely, there will be less variance
6
Q
when is the variance largest
A
when p = 1/2
7
Q
what is binomial trials
A
a sum of n independent bernpulli random variables
8
Q
how to calculate p of k successes out of N trials
binomial
A
(N choose k)*(p success)^no of successes * (p failure)^no of failures
9
Q
expected value of a binomial trial
A
E(X) = np
n = number of trials p = p of success
10
Q
variance in a binomial trial
A
np(1-p)
p = p of success n = number of trials
