Chapter 4
Exercises 4.1 to 4.15
707 + 769 1476
9707
=
= 738 . There are a couple of outliers at the high
= 970.7 median =
10
2
2
end of the data set and so the mean is influenced by these more than the median. For this reason, the
median is more represent
Chapter 5
Exercises 5.1 5.16
5.1
A positive correlation would be expected, since as temperature increases cooling costs
would also increase.
b
A negative correlation would be expected, since as interest rates climb fewer people would
be submitting applica
Chapter 13
Exercises 13.1 13.11
When x = 1000, y = 5 + 0.017(1000) = 12
When x = 2000, y = 5 + 0.017(2000) = 29
When x = 2100, y = 5 + (0.017)(2100) = 30.7
d
0.017
e
0.017(100) = 1.7
f
It is stated that the community where the given regression model is va
Chapter 14
Exercises 14.1 14.14
14.1
A deterministic model does not have the random deviation component e, while a probabilistic
model does contain such a component.
Let
y=
total number of goods purchased at a service station which sells only one grade
of
Chapter 3
Exercises 3.1 to 3.16
3.1
View of U.S. Economy
Stressed &
Stretched
Unflustered
Struggler
Anxious
Optimist
Comfortable
3.2
Gender
0.
Relative
0.
0.
Women
0.
Me
0.
0.
0
Advantage
being a
Advantag
being a
No
Don't
Respons
More than half the women
Chapter 11
Exercises 11.1 11.28
11.1
x
1
x
2
= 1 2 = 30 25 = 5
x1 x2 =
2
1 2
2
n1
+
n2
=
(2 )2 (3 )2
+
=
40
50
4
9
+
= 0.28 = 0.529
40 50
Since both n1 and n 2 are large, the sampling distribution of x1 x2 is approximately normal. It is
centered at 5 and
Chapter 12
Exercises 12.1 12.13
12.1
0.035 < P-value < 0.040
d
P-value < 0.001
e
P-value > 0.100
a
df = 3 and X 2 = 6.4. From Appendix Table IX, 0.090 < P-value < 0.095. Since the
P-value exceeds , Ho would not be rejected. The data are consistent with th
Chapter 7
Exercises 7.1 7.10
7.1
continuous
c
discrete
d
discrete
e
continuous
a
continuous
b
continuous
c
continuous
d
discrete
e
continuous
f
continuous
g
7.3
discrete
b
7.2
a
discrete
a
b
P(individual does not have earthquake insurance) = 0.4
173
7.4
a
Chapter 10
Exercises 10.1 10.10
10.1
x = 50 is not a legitimate hypothesis, because x is a statistic, not a population characteristic.
Hypotheses are always expressed in terms of a population characteristic, not in terms of a sample
statistic.
10.2
Those
Chapter 9
Exercises 9.1 9.10
9.1
Statistic II would be preferred because it is unbiased and has smaller variance than the other two.
9.2
An unbiased statistic is generally preferred over a biased statistic, because there is no long run
tendency for the un
Chapter 8
Exercises 8.1 8.13
8.1
A statistic is any quantity computed from the observations in a sample. A population characteristic
is a quantity which describes the population from which the sample was taken.
8.2
The quantity denotes the mean of the pop
Devore & Peck, Chapter 6
Exercises 6.1 6.14
6.1
In the long run, 1% of all people who suffer cardiac arrest in New York City survive.
b
1% of 2329 is .01(2329) = 23.29. So in this study there must have been only 23 or 24 survivors.
a
Out of the many incom
Chapter 2
Exercises 2.1 2.26
2.1
The first method is as follows. Write the graduates names on slips of paper (one name per slip).
Place the slips of paper in a container and thoroughly mix the slips. Then, select 20 slips (graduates),
one at a time withou
Chapter 1
Exercise 1.1 1.7
1.1
Descriptive statistics is made up of those methods whose purpose is to organize and summarize a
data set. Inferential statistics refers to those procedures or techniques whose purpose is to generalize
or make an inference ab