stats

Question 1

var(x)

Answer 1

e(x^2)-e(x)^2

Question 2

e(ax+b)

Answer 2

ae(x)+b

Question 3

var(ax+b)

Answer 3

a^2var(x)

Question 4

conditions for poisson

Answer 4

• independently
• singly
• constant average rate

Question 5

mean and var of poisson

Answer 5

lambda

Question 6

conditions for approximating binomial as poisson

Answer 6

• n is large
• p is is small

Question 7

how to approximate binomial to poisson

Answer 7

lambda = np

Question 8

what is geo used for

Answer 8

number of trials for one success

Question 9

geo P(X=x)

Answer 9

p(1-p)^x-1

Question 10

geo P(X<=x)

Answer 10

1-(1-p)^x-1

Question 11

geo P(X>x)

Answer 11

(1-p)^x

Question 12

geo P(x>=x)

Answer 12

(1-p)^x-1

Question 13

mean of geo

Answer 13

1/p

Question 14

var of geo

Answer 14

(1-p)/p^2

Question 15

what is -ve B used for

Answer 15

number of trials to get a set number of successes

Question 16

-ve B P(X=x)

Answer 16

x-1Cr-1 p^r(1-p)^x-r

Question 17

mean of -ve B

Answer 17

r/p

Question 18

var of -ve B

Answer 18

r(1-p)/p^2

Question 19

CLT

Answer 19

sample size of n from any dist with mean mu and var sigma^2 then mean x is canr be distributed N(mu, sigma^2/n)

Question 20

goodness of fit formula

Answer 20

(Oi-Ei)^2/Ei

Question 21

degrees of freedom

Answer 21

cells-constraints (at least 1)

Question 22

if X^2 exceeds critical val

Answer 22

reject null

Question 23

Ei for contingency tables

Answer 23

(row tot x column tot)/total

Question 24

if P is less than significance level

Answer 24

reject Ho

Question 25

how is significance leveln affected in 2 tailed test

Answer 25

half sig level given

Question 26

what ahppens if a val is in critical region

Answer 26

reject Ho

Question 27

pgf of binomial

Answer 27

Gx(t)=(1-p+pt)^n

Question 28

pgf of poisson

Answer 28

Gx(t)=e^lambda(t-1)

Question 29

pgf of geo

Answer 29

Gx(t)= pt/1-(1-p)t

Question 30

pgf of -ve B

Answer 30

Gx(t)=(pt/1-(1-p)t)^r

Question 31

E(x) pgf

Answer 31

G'x(1)

Question 32

Var(X) pgf

Answer 32

G''x(1)+G'x(1)-(G'x(1))^2

Question 33

Gz(t) where Z=X+Y

Answer 33

Gy(t) x Gx(t)

Question 34

Gy(t) where Y=aX+b

Answer 34

t^bGx(t^a)

Question 35

type 1 error

Answer 35

reject null when true same as sig level

Question 36

type 2 error

Answer 36

accept null when false

Question 37

size

Answer 37

p(type 1)

Question 38

power

Answer 38

1-p(type 2)