Basic Practice of Statistics - 3rd Edition
!
"
!
#
%
$
&'
!
!
)
!
!
'
!
(
&'
'
!
!
&'
'
*
!
*
!
!
'
!
!
(
+ !,
-
! .
&'
/
#
'
(
'
"
!
!
!
"
'
!
"
$
$
!
(
'
Chapter 7
!
1
Basic Practice of Statistics - 3rd Edition
4
#
0
&'
'
1
2
!
!
3
!
A recent newspaper article concluded
that smoking marijuana at least three
times a week resulted in lower grades
in college. How do you think the
researchers came to this conclusion?
Do you believe it? Is there a more
reasonable conclusion?
!
!
!
The Effect of Hypnosis
on the
Immune System
reported in Science News, Sept. 4, 1993, p. 153
!
(
! !
0
! !
77
78
Chapter 7
Objective:
To determine if hypnosis strengthens the
disease-fighting capacity of immune cells.
!
56
!
The Effect of Hypnosis
on the
Immune System
!
0
3
3
!
0
'
"
'
!
$
(
2
Basic Practice of Statistics - 3rd Edition
!
!
*
!
1
0
! !
$
3
0
The Effect of Hypnosis
on the
Immune System
What is the population?
2
What is the sample?
!
!
The Effect of Hypnosis
on the
Immune System
The Effect of Hypnosis
on the
Immune System
Is this an experiment
or
an observational study?
Does hypnosis and
mental exercise affect the
immune system?
!
Weight Gain Spells
Heart Risk for Women
“Weight, weight change, and coronary heart
disease in women.” W.C. Willett, et. al., vol. 273(6),
Journal of the American Medical Association, Feb.
8, 1995.
(Reported in Science News, Feb. 4, 1995, p. 108)
Chapter 7
!
Weight Gain Spells
Heart Risk for Women
Objective:
To recommend a range of body mass index
(a function of weight and height) in terms of
coronary heart disease (CHD) risk in women.
3
Basic Practice of Statistics - 3rd Edition
!
!
!
66 !
9: 5
&
&
=
996";9;
!
!
$
7<
% (
#
#
9> !
98:8
(
3
9;(
!
!
(
%
!"
(
$
"
"
*
!
99
99
9
9
8>
8>
>>
9;
86?
(
Weight Gain Spells
Heart Risk for Women
$ !
5>?
$ !
:8?
$ !
>>
956?
What is the population?
$ !
What is the sample?
!
Chapter 7
!
Weight Gain Spells
Heart Risk for Women
Weight Gain Spells
Heart Risk for Women
Is this an experiment
or
an observational study?
Does weight gain in
women increase their risk
for CHD?
4
Basic Practice of Statistics - 3rd Edition
)
@
@
!
$+
9<<"<<<
#
!
B
"
%
$
"
'"
(
>(6?
%
$
" 9::
C
1
❖)
A !
D2
!
1
1
$ !2
&
!
!
$D2
!
!
&
9<
+
$ !
!
0
!
/
/
1
2
#
#
)
<
( 56>
!
:
'
! $ !
#& 9 B
!
#& 8 .
! $ !
9<<<
Chapter 7
#
)
$
!
!
9<<
9<
!
<<" <9"D" ::
! $ !
<<<" <<9" D" :::
!
5
Basic Practice of Statistics - 3rd Edition
!
!
$
"
"
!"
"
"
C
&'
!
*
.
E
66?
!
F
!
8<?
6?
"
8<?
!
A stratified random sample of 100 students could be chosen
as follows: select a SRS of 55 undergraduates, a SRS of 20
graduates, a SRS of 5 first professional students, and a SRS
of 20 special students; combine these 100 students.
!
" !
"
"D
,
$+
9<<"<<<
#
.
B
"
%
$
"
'"
(
,
%
G
$
!
$ !
!
+
H
Chapter 7
6
Basic Practice of Statistics - 3rd Edition
Response Bias
)
- $
+
-
* *
!(
.
+
$! &
!
- 9: ;
!1
- (2
#
(
!
!
I
!
F
,
-
9<*95" 9::6" ( 75
!
"
/
+
$
9: 6
I
$
+
4
'
)
A newsletter distributed by a politician to his
constituents gave the results of a “nationwide
survey on Americans’ attitudes about a variety of
educational issues.”
1J !
K8<
"
!
K8<
"
!/2
!
!/2
1J !
One of the questions asked was, “Should your
legislature adopt a policy to assist children in failing
schools to opt out of that school and attend an
alternative school--public, private, or parochial--of
the parents’ choosing?”
From the wording of this question, can you
speculate on what answer was desired? Explain.
+
.
.
1
1J
!
(2
%
%
!
!!
1
!
$J
/
J
! "
!
%
+
Chapter 7
+
)
/2
! !
/
!
!
-
!
' !
!
!
*
$
/2
!
*
$
!
!
/
/
7
Basic Practice of Statistics - 3rd Edition
+
4
1%
LLL
1%
!
J
!
@
/
(2
!
!
(2
(
J
$
$
@
!
!!
"
$ !
**
Chapter 7
8