stats Flashcards
1
Q
SD equation
A
sqrt (sum (xi - x̄)^2 / x-1)
for sample
2
Q
mutually exclusive
A
they cant both happen
3
Q
exhaustive
A
at least one must happen
4
Q
how to show that A and B are independent
A
P(A|B) = P(A)
P(A∩B) = P(A) x P(B)
5
Q
E(X) and Var(X) for binomial
A
E(X) = np
Var(X) = npq
6
Q
E(X) and Var(X) for geometric
A
E(x) = 1/p
Var(x) = q/p^2
7
Q
Geometric distribution equations
A
P(X=x) = q^(x-1) x p
P(X≤x) = 1-q^x
P(X>x) = q^x
8
Q
geometric mode and median
A
mode = 1
median = P(X≤m) = 1/2
9
Q
Related random variables
A
G(y) = P(Y ≤ y)
