Search
Create
Log in
Sign up
Log in
Sign up
Further Statistics
STUDY
Flashcards
Learn
Write
Spell
Test
PLAY
Match
Gravity
Terms in this set (11)
Discrete Random Variable: E(X)
Σx(P(X=x))
Discrete Random Variable: Var(X)
E(X²) - (E(X))²
Discrete Random Variable: E(aX + b)
aE(X) + b
Discrete Random Variable: Var(aX + b)
a²(Var(X))
Discrete Random Variable: E(X + Y)
E(X) + E(Y)
Discrete Random Variable: Var(X + Y)
Var(X) + Var(Y)
Discrete Random Variable: Var(X - Y)
Var(X) + Var(Y)
For the Poisson distribution to be a good model...
- Events must occur independently
- Events must occur singly (in space/time)
- Events must occur at a constant average rate (so that the mean number of events in an interval is proportional to the length of the interval.
If X ~ Po(λ) and Y ~ Po(μ), X + Y ~ .....
X + Y ~ (λ + μ)
Under what circumstances is the Poisson distribution a good approximation for the binomial distribution?
- n is large
- p is small
(np < 10 to be ideal)
X ~ Geo(p):
P(X ≤ x)
1 - (1 - p)ˣ
;