Stats Test 2

Front 1

Combination

Back 1

select K out of N objects, when the order does not matter.

N!
---------
(N-K)!K!

Front 2

Permutation

Back 2

select K out of N objects, when the order does matter.

N!
------
(N-K)!

Front 3

addition law

Back 3

P(AuB) = P(A) + P(B) - P(ANB)

Front 4

mutually exclusive

Back 4

2 events that can not happen simultaneously.

P(AnB)=0

Front 5

P(A|B)=

Back 5

P(AnB)
----------
P(B)

Front 6

Independent events

Back 6

2 events where the occurance of 1 has no effect of the probability of another happening.

P(A|B)=P(A)

Front 7

Multiplication Law

Back 7

P(AnB)=P(A|B)xP(B)

Front 8

Multiplication law for independent events

Back 8

P(AnB)=P(A)xP(B)

Front 9

discrete random variable

Back 9

finite number of values,
or
infinate number of values with each seperated by a distinct amount

Front 10

continuous random variable

Back 10

infinate number of values within a range.

Front 11

Variance of discrete random variables

Back 11

2
E((X-m) x F(X))

Front 12

expected value of discrete random variable

Back 12

E(X x F(X)

Front 13

Binomial Experiment

Back 13

1)sequence of N identical trials

2) 2 outcomes possible, success/failure

3) probability does not change from trial to trial

4) trials are independent

Front 14

Binomial possibility

f(x)=

Back 14

n x (n-x)
x P (1-P)

Front 15

expected value of binomial

Back 15

NP

Front 16

variance of binomial

Back 16

NP(1-P)

Front 17

poisson distribution

Back 17

determines the probability of X successes in am interval

1) probability of occurance is same for any 2 intervals of equal length

2) the occurance in 1 interval in independent of any other occurance

Front 18

poisson probability

f(x)=

Back 18

x -m
m e
----------
x!

Front 19

expected value of poisson

Back 19

m

Front 20

variance of poisson

Back 20

m