Chapter 12: Regression and Correlation
28.
yi
We wish to find b 1 to minimize
2
yi
b1 xi
xi
2
f b1 . Equating f b1 to 0 yields
xi y i
b1 x i2 and b1
. The least squares
xi2
0 so xi y i
is thus
1
1
estimator of
b1 xi
xi Yi
.
xi2
29.
a.
x from each xi shi
Chapter 7: Point Estimation
CHAPTER 7
Section 7.1
1.
a.
We use the sample mean,
x
xi
n
x to estimate the population mean
.
3753
113.73
33
b.
We use the sample median, ~ 113 , to estimate the population median.
x
c.
We use the sample standard deviation, s
Chapter 8: Statistical Intervals Based on a Single Sample
CHAPTER 8
Section 8.1
1.
a.
z
2.81 implies that
2
level is
100 1
%
1.44 for
z
c.
2.81
.0025 , so
.005 and the confidence
99.5% .
21
b.
99.7% implies that
2
1
2
.15 , and 100 1
1.44
.003 ,
2
.0015 ,
Chapter 9: Tests of Hypotheses Based on a Single Sample
CHAPTER 9
Section 9.1
1.
a.
Yes. It is an assertion about the value of a parameter.
b.
No. The sample median
c.
No. The sample standard deviation s is not a parameter.
d.
Yes. The assertion is that t
Chapter 12: Regression and Correlation
CHAPTER 12
Section 12.1
1.
a.
Stem and Leaf display of temp:
17 0
17 23
17 445
17 67
17
18 0000011
18 2222
18 445
18 6
18 8
stem = tens
leaf = ones
180 appears to be a typical value for this data. The distribution is
STAT 3120 Midterm I Mar 2015
Name:
Computing ID:
Pledge: On my honor, I pledge that I have neither given nor received help
on this exam.
SIGNATURE:
Direction:
1. There are 3 questions which worth 50 points in total.
2. Intermediate steps are important to
STAT 3120 Midterm II April 2015
Name:
Computing ID:
Pledge: On my honor, I pledge that I have neither given nor received help
on this exam.
SIGNATURE:
Directions:
1. There are 3 questions which worth 50 points in total.
2. Intermediate steps are important