One.  Clark Heter is an industrial engineer at Lyons Products. He would like to determine whether there are more units produced on the night shift than on the day shift. A sample of 50 day-shift workers showed that the mean number of units produced was 353, with a population standard deviation of 25. A sample of 55 night-shift workers showed that the mean number of units produced was 363, with a population standard deviation of 31 units. At the .01 significance level, is the number of units produced on the night shift larger? (a) This is a -tailed test. (b) The decision rule is to reject  if Z < . (Negative amount should be indicated by a minus sign. Round your answer to 2 decimal places.) (c) The test statistic is Z = . (Negative amount should be indicated by a minus sign. Round your answer to 2 decimal places.) TWO Each month the National Association of Purchasing Managers publishes the NAPM index. One of the questions asked on the survey to purchasing agents is: Do you think the economy is contracting? Last month, of the 310 responses, 164 answered yes to the question. This month, 177 of the 291 responses indicated they felt the economy was contracting. At the .02 significance level, can we conclude that a larger proportion of the agents believe the economy is contracting this month? pc =  . (Do not round the intermediate value. Round your answer to 2 decimal places.) The test statistic is  . (Negative amount should be indicated by a minus sign. Do not round the intermediate value. Round your answer to 2 decimal places.) Decision:  the null. H0 : π1 ≥ π2 THREE The manufacturer of an MP3 player wanted to know whether a 10 percent reduction in price is enough to increase the sales of its product. To investigate, the owner randomly selected eight outlets and sold the MP3 player at the reduced price. At seven randomly selected outlets, the MP3 player was sold at the regular price. Reported below is the number of units sold last month at the sampled outlets.   Regular price 133   124   88   112   144   128   96     Reduced price  124   134   152   134   114   109   113   114   At the .050 significance level, can the manufacturer conclude that the price reduction resulted in an increase in sales? Hint: For the calculations, assume the Reduced price as the first sample. The pooled variance is . (Round your answer to 2 decimal places.) The test statistic is . (Round your answer to 2 decimal places.)  H0. FOUR One of the music industry's most pressing questions is: Can paid download stores contend nose-to-nose with free peer-to-peer download services? Data gathered over the last 12 months show Apple's iTunes was used by an average of 1.81 million households with a sample standard deviation of .47 million family units. Over the same 12 months WinMX (a no-cost P2P download service) was used by an average of 2.21 million families with a sample standard deviation of .32 million. Assume the population standard deviations are not the sam.

1. One. Clark Heter is an industrial engineer at Lyons Products.
He would like to determine whether there are more units
produced on the night shift than on the day shift. A sample of
50 day-shift workers showed that the mean number of units
produced was 353, with a population standard deviation of 25.
A sample of 55 night-shift workers showed that the mean
number of units produced was 363, with a population standard
deviation of 31 units.
At the .01 significance level, is the number of units produced on
the night shift larger?
(a)
This is a -tailed test.
(b)
The decision rule is to reject if Z < . (Negative amount should
be indicated by a minus sign. Round your answer to 2 decimal
places.)
(c)
The test statistic is Z = . (Negative amount should be indicated
by a minus sign. Round your answer to 2 decimal places.)
TWO
Each month the National Association of Purchasing Managers
publishes the NAPM index. One of the questions asked on the
survey to purchasing agents is: Do you think the economy is
contracting? Last month, of the 310 responses, 164 answered
yes to the question. This month, 177 of the 291 responses
indicated they felt the economy was contracting.
At the .02 significance level, can we conclude that a larger
proportion of the agents believe the economy is contracting this

2. month?
pc = . (Do not round the intermediate value. Round your
answer to 2 decimal places.)
The test statistic is . (Negative amount should be indicated by a
minus sign. Do not round the intermediate value. Round your
answer to 2 decimal places.)
Decision: the null. H0 : π1 ≥ π2
THREE
The manufacturer of an MP3 player wanted to know whether a
10 percent reduction in price is enough to increase the sales of
its product. To investigate, the owner randomly selected eight
outlets and sold the MP3 player at the reduced price. At seven
randomly selected outlets, the MP3 player was sold at the
regular price. Reported below is the number of units sold last
month at the sampled outlets.
Regular price
133
124
88
112
144
128
96
Reduced price
124
134
152
134
114
109

3. 113
114
At the .050 significance level, can the manufacturer conclude
that the price reduction resulted in an increase in sales? Hint:
For the calculations, assume the Reduced price as the first
sample.
The pooled variance is . (Round your answer to 2 decimal
places.)
The test statistic is . (Round your answer to 2 decimal places.)
H0.
FOUR
One of the music industry's most pressing questions is: Can paid
download stores contend nose-to-nose with free peer-to-peer
download services? Data gathered over the last 12 months show
Apple's iTunes was used by an average of 1.81 million
households with a sample standard deviation of .47 million
family units. Over the same 12 months WinMX (a no-cost P2P
download service) was used by an average of 2.21 million
families with a sample standard deviation of .32 million.
Assume the population standard deviations are not the same.
(A)
Find the degrees of freedom for unequal variance test. (Round
down your answer to nearest whole number.)
Degrees of freedom
(B)
State the decision rule for .02 significance
level: H0: A = W; H1: A ≠ W . (Negative amounts should be

4. indicated by a minus sign. Round your answer to 3 decimal
places.)
Reject H0 if t < or t >
(C)
Compute the value of the test statistic. (Negative amount should
be indicated by a minus sign.Round your answer to 2 decimal
places.)
Value of the test statistic
(D)
Test the hypothesis of no difference in the mean number of
households picking either variety of service to download songs.
Use the .02 significance level.
H0. There is difference in the mean number of
households picking either variety of service to download songs.
FIVE
When only two treatments are involved, ANOVA and the
Student t test (Chapter 11) result in the same conclusions.
Also, . As an example, suppose that 14 randomly selected
students were divided into two groups, one consisting of 6
students and the other of 8. One group was taught using a
combination of lecture and programmed instruction, the other
using a combination of lecture and television. At the end of the
course, each group was given a 50-item test. The following is a
list of the number correct for each of the two groups. Using
analysis of variance techniques, test the null hypothesis, that
the two mean test scores are equal.

5. Lecture and
Programmed
Instruction
Lecture and
Television
12
37
14
27
26
37
28
21
13
25
15
27
26
23
(a-1)
Complete the ANOVA table. (Round SS, MS and F values to 2
decimal places.)
Source
SS
df
MS
F
Factors

6. Error
Total
(a-2)
Use a level of significance. (Round your answer to 2 decimal
places.)
The test statistic is F
(b)
Using the t test from Chapter 11, compute t.(Negative amount
should be indicated by a minus sign. Round your answer to 2

7. decimal places.)
t
(c)
There is in the mean test scores
SIX
The following hypotheses are given.
Ho : σ1² ≤ σ2²
H1 : σ1² > σ2²
A random sample of five observations from the first population
resulted in a standard deviation of 12. A random sample of
seven observations from the second population showed a
standard deviation of 7. At the .01 significance level, is there
more variation in the first population?
The test statistic is . (Round your answer to 2 decimal places.)
Decision: Ho
SEVEN
Given the following sample information, test the hypothesis that
the treatment means are equal at the .05 significance level.
Treatment 1
Treatment 2
Treatment 3
8
3
3
11
2

8. 4
10
1
5
3
4
2
(a-1)
State the null hypothesis and the alternate hypothesis.
Null hypothesis
Ho: μ1 = μ2 = μ3
Ho: μ1 = μ2
a-2)
Alternative hypothesis
H1: Treatment means are all the same
H1: Treatment means are not all the same
b)
What is the decision rule? (Round your answer to 2 decimal
places.)
Reject Ho if F >
c)

9. Compute SST, SSE, and SS total. (Round your answers to 2
decimal places.)
SST
SSE
SS total
d)
Complete an ANOVA table. (Round F, SS to 2 decimal places
and MS to 3 decimal places.)
Source
SS
df
MS
F
Treatments
Error

10. Total
e)
State your decision regarding the null hypothesis.
Reject H0.
Do not reject H0.
f)
If H0 is rejected, can we conclude that treatment 1 and
treatment 2 differ? Use the 95 percent level of confidence.
, we conclude that the treatments 1 and 2 have different
means.
EIGHT
There are four radio stations in Midland. The stations have
different formats (hard rock, classical, country/western, and
easy listening), but each is concerned with the number of
minutes of music played per hour. From a sample of 10 hours
from each station, the following sample means were offered.

11. SS total = 650.75
(a)
SST = . (Round your answer to 3 decimal places.)
(b)
SSE = . (Round your answer to 3 decimal places.)
(c)
Complete an ANOVA table. (Round SS, MS, F to 3 decimal
places and df to nearest whole number.)
SS
df
MS
F
Treatments
Error
Total

12. (d)
At the .05 significance level, is there a difference in the
treatment means?
NINE
Given the following sample information, test the hypothesis that
the treatment means are equal at the .05 significance level.
Treatment 1
Treatment 2
Treatment 3
3
9
6
2
6
3
5
5
5
1
6
5
3
8

13. 5
1
5
4
4
1
7
5
6
4
Click here for the Excel Data File
(a)
Ho : μ1 μ2 μ3.
H1 : Treatment means all the same
(b)
Reject Ho if F > .(Round your answer to 2 decimal places.)
(c)
SST = SSE = SS total = (Round your answers to 2 decimal
places.)
(d)
Complete the ANOVA table. (Round SS, MS and F values to 2

14. decimal places.)
Source
SS
df
MS
F
Treatments
Error
Total

15. (e)
Decision: Ho
(f)
Find the 95% confidence interval for the difference between
treatment 2 and 3. (Round your answers to 2decimal places.)
95% confidence interval is: ±
We can conclude that the treatments 2 and 3 are
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