Chapter
11:
Chi-squared
tests
Types
of
chi-squared
tests
1.
Goodness
of
fit:
distribution
of
a
single
categorical
variable
in
a
population
(are
the
proportions
what
they’re
claimed
to
be?)
2.
Test
for
homogeneity:
is
everything
the
same?-
multiple
variables
3.
Test
for
independence:
does
x
cause
y
or
is
it
just
chance?
-
distribution
is
always
skewed
right:
pχ2 value
is
ALWAYS
on
right
tail
Goodness
of
fit
(GOF)
1.
all
proportions
are
what
they’re
claimed
to
be𝐻0:
the
claim
is
NOT
correct:
at
least
2
proportions
differ
from
their𝐻𝐴:
hypothesized
populations
=.05α
*Define
all
parameters*
2.
State
you’re
doing
a
GOF
testχ2 Conditions
SRS
10%
All
expected
counts
are
at
least
5
3.
-
Calculate
expected
values
(n
times
expected
proportions)
-
Plug
into∑(𝑂−𝐸)2
𝐸
11:
Chi-squared
tests
Types
of
chi-squared
tests
1.
Goodness
of
fit:
distribution
of
a
single
categorical
variable
in
a
population
(are
the
proportions
what
they’re
claimed
to
be?)
2.
Test
for
homogeneity:
is
everything
the
same?-
multiple
variables
3.
Test
for
independence:
does
x
cause
y
or
is
it
just
chance?
-
distribution
is
always
skewed
right:
pχ2 value
is
ALWAYS
on
right
tail
Goodness
of
fit
(GOF)
1.
all
proportions
are
what
they’re
claimed
to
be𝐻0:
the
claim
is
NOT
correct:
at
least
2
proportions
differ
from
their𝐻𝐴:
hypothesized
populations
=.05α
*Define
all
parameters*
2.
State
you’re
doing
a
GOF
testχ2 Conditions
SRS
10%
All
expected
counts
are
at
least
5
3.
-
Calculate
expected
values
(n
times
expected
proportions)
-
Plug
into∑(𝑂−𝐸)2
𝐸
