DEVEME2_0321500458 pp2.qxd
12/26/07
11:56 AM
Page 3
Quick Guide to Inference
Think
Show
One
group
or two?
Inference
about?
One
sample
Proportions
Two
independent
groups
Means
Model
Chapter
19
p̂
p̂q̂
Å n
z
p
1-Proportion
z-Test
p0 q0
Å n
z
p1 2 p2
p̂1 2 p̂2
s
m
y
Two
independent
groups
2-Sample t-Test
2-Sample t-Interval
t
df from
technology
m1 2 m2
y1 2 y2
Matched
pairs
Paired t-Test
Paired t-Interval
t
df 5 n 2 1
md
d
One
sample
Goodnessof-Fit
x2
df 5 cells 2 1
Many
independent
groups
Homogeneity
x2 Test
Linear Regression
t-Test or Confidence
Interval for b
One
sample
One
group
or two?
*Confidence
Interval for mn
Procedure
s 22
s 21
1
Å n1
n2
t
df 5 n 2 2
Model
24
sd
"n
x2
df 5 (r 2 1)(c 2 1)
25
(Obs 2 Exp) 2
Exp
26
b1
b1
se
sx !n 2 1
(compute with technology)
mn
ŷn
SE 2 (b1 ) ? (xn 2 x ) 2 1
yn
ŷn
Parameter Estimate
Copyright 2010 Pearson Education, Inc.
Å
Å
SE 2 (b1 ) ? (xn 2 x ) 2 1
SE
22
23
"n
a
Independence
x2 Test
22
y1 1 y2
p̂q̂
p̂q̂
1
, p̂ 5
n2
n1 1 n2
Å n1
2-Proportion
z-Test
t
df 5 n 2 1
One
sample
20, 21
p̂ q̂
p̂1 q̂1
1 2 2
Å n1
n2
2-Proportion
z-Interval
*Prediction
Interval for yn
Inference
about?
SE
t-Interval
t-Test
Association
(two
quantitative
variables)
Estimate
1-Proportion
z-Interval
Independence
(two
categorical
variables)
Parameter
One
sample
Distributions
(one categorical
variable)
Procedure
Tell?
se2
n
27
se2
1 se2
n
Chapter