Transcript les4e_alq_08ac

Active Learning Lecture Slides
For use with Classroom Response Systems
Chapter 8: Hypothesis Testing with
Two Samples
Elementary Statistics:
Picturing the World
Fourth Edition
by Larson and Farber
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slide 4- 1
Classify the pair of samples as dependent
or independent.
Sample 1: Exam scores for 25 students in
Dr. Smith’s morning statistics class.
Sample 2: Exam scores for 28 students in
Dr. Smith’s afternoon statistics class.
A. Dependent
B. Independent
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slide 8- 2
Classify the pair of samples as dependent
or independent.
Sample 1: Exam scores for 25 students in
Dr. Smith’s morning statistics class.
Sample 2: Exam scores for 28 students in
Dr. Smith’s afternoon statistics class.
A. Dependent
B. Independent
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slide 8- 3
State the null and alternative hypotheses.
The mean cell phone bill for females (1) is
higher than the mean cell phone for males
(2).
A. H0: μ1 > μ2 Ha: μ1 ≤ μ2
B. H0: μ1 < μ2 Ha: μ1 ≥ μ2
C. H0: μ1 ≤ μ2 Ha: μ1 > μ2
D. H0: μ1 ≥ μ2 Ha: μ1 < μ2
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slide 8- 4
State the null and alternative hypotheses.
The mean cell phone bill for females (1) is
higher than the mean cell phone for males
(2).
A. H0: μ1 > μ2 Ha: μ1 ≤ μ2
B. H0: μ1 < μ2 Ha: μ1 ≥ μ2
C. H0: μ1 ≤ μ2 Ha: μ1 > μ2
D. H0: μ1 ≥ μ2 Ha: μ1 < μ2
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slide 8- 5
Find the standardized test statistic z for the
following situation:
Claim: μ1 = μ2; x1  81 . 2 s1 = 3.7 n1 = 40
x 2  78 . 9 s2 = 2.1 n2 = 35
A. z = 3.25
B. z = 3.36
C. z = 2.45
D. z = 5.89
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slide 8- 6
Find the standardized test statistic z for the
following situation:
Claim: μ1 = μ2; x1  81 . 2 s1 = 3.7 n1 = 40
x 2  78 . 9 s2 = 2.1 n2 = 35
A. z = 3.25
B. z = 3.36
C. z = 2.45
D. z = 5.89
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slide 8- 7
Find the pooled estimate of the standard
deviation ˆ for the following situation:
x1  6 . 2
x2  6 .9
s1 = 1.3
s2 = 0.8
n1 = 12
n2 = 15
A. ˆ  1 . 0 5
B. ˆ  1 . 1 0
C. ˆ  1 . 0 1
D. ˆ  1 . 0 9
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slide 8- 8
Find the pooled estimate of the standard
deviation ˆ for the following situation:
x1  6 . 2
x2  6 .9
s1 = 1.3
s2 = 0.8
n1 = 12
n2 = 15
A. ˆ  1 . 0 5
B. ˆ  1 . 1 0
C. ˆ  1 . 0 1
D. ˆ  1 . 0 9
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slide 8- 9
Find the standardized test statistic t for the
following situation (assume the
populations are normally distributed and
the population variances are equal):
Claim: μ1 = μ2; x1  6 . 2
s1 = 1.3 n1 = 12
x 2  6 . 9 s2 = 0.8 n2 = 15
A. t = –1.72
B. t = –1.63
C. t = –0.63
D. t = –0.69
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slide 8- 10
Find the standardized test statistic t for the
following situation (assume the
populations are normally distributed and
the population variances are equal):
Claim: μ1 = μ2; x1  6 . 2
s1 = 1.3 n1 = 12
x 2  6 . 9 s2 = 0.8 n2 = 15
A. t = –1.72
B. t = –1.63
C. t = –0.69
D. t = –0.63
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slide 8- 11
State the null and alternative hypotheses.
The mean score before and after a
treatment are the same.
Before
After
7
5
5
4
8
4
3
2
6
7
4
3
A. H0: μ1 = μ2 Ha: μ1 ≠ μ2
B. H0: μ1 ≠ μ2 Ha: μ1 = μ2
C. H0: μd = 0
Ha: μd ≠ 0
D. H0: μd ≠ μ2 Ha: μd = 0
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slide 8- 12
State the null and alternative hypotheses.
The mean score before and after a
treatment are the same.
Before
After
7
5
5
4
8
4
3
2
6
7
4
3
A. H0: μ1 = μ2 Ha: μ1 ≠ μ2
B. H0: μ1 ≠ μ2 Ha: μ1 = μ2
C. H0: μd = 0
Ha: μd ≠ 0
D. H0: μd ≠ μ2 Ha: μd = 0
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slide 8- 13
Find the mean of the difference between
the paired data entries in the dependent
samples, d .
Before
After
7
5
5
4
8
4
3
2
6
7
4
3
A. 4.17
B. 4.83
C. 1.33
D. 5.5
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slide 8- 14
Find the mean of the difference between
the paired data entries in the dependent
samples, d .
Before
After
7
5
5
4
8
4
3
2
6
7
4
3
A. 4.17
B. 4.83
C. 1.33
D. 5.5
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slide 8- 15
State the null and alternative hypotheses.
The proportion of female accountants (1) is
less than the proportion of male
accountants (2).
A. H0: p1 < p2 Ha: p1 ≥ p2
B. H0: p1 ≤ p2 Ha: p1 > p2
C. H0: p1 = p2 Ha: p1 ≠ p2
D. H0: p1 ≥ p2 Ha: p1 < p2
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slide 8- 16
State the null and alternative hypotheses.
The proportion of female accountants (1) is
less than the proportion of male
accountants (2).
A. H0: p1 < p2 Ha: p1 ≥ p2
B. H0: p1 ≤ p2 Ha: p1 > p2
C. H0: p1 = p2 Ha: p1 ≠ p2
D. H0: p1 ≥ p2 Ha: p1 < p2
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slide 8- 17
Find the standardized test statistic z for the
following situation:
Claim: p1 > p2; x1 = 100
x2 = 90
n1 = 250
n2 = 300
A. z = 2.46
B. z = 1.45
C. z = 0.35
D. z = 3.37
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slide 8- 18
Find the standardized test statistic z for the
following situation:
Claim: p1 > p2; x1 = 100
x2 = 90
n1 = 250
n2 = 300
A. z = 2.46
B. z = 1.45
C. z = 0.35
D. z = 3.37
Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley
Slide 8- 19