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Active Learning Lecture Slides
For use with Classroom Response Systems
Chapter 18:
Sampling Distribution Models
Intro Stats
Third Edition
by De Veaux, Velleman, Bock
Copyright © 2009 Pearson Education, Inc.
Slide 18 - 1
A certain population is approximately normal. We
want to estimate its mean, so we will collect a
sample. Which should be true if we use a large
sample rather than a small one?
I.
The distribution of our sample data will be
approximately normal.
II. The sampling distribution of the sample means will be
approximately normal.
III. The variability of the sample means will be smaller.
A. I only
B. II only
C. III only
D. II and III
E. I, II, and III
Copyright © 2009 Pearson Education, Inc.
Slide 18 - 2
A certain population is approximately normal. We
want to estimate its mean, so we will collect a
sample. Which should be true if we use a large
sample rather than a small one?
I.
The distribution of our sample data will be
approximately normal.
II. The sampling distribution of the sample means will be
approximately normal.
III. The variability of the sample means will be smaller.
A. I only
B. II only
C. III only
D. II and III
E. I, II, and III
Copyright © 2009 Pearson Education, Inc.
Slide 18 - 3
Which of the following is not an assumption or
condition that needs to be checked for the
one-proportion z-test?
A. Independence
B. Randomization
C. 10% Condition
D. Success/Failure Condition
E. Nearly Normal Condition
Copyright © 2009 Pearson Education, Inc.
Slide 18 - 4
Which of the following is not an assumption or
condition that needs to be checked for the
one-proportion z-test?
A. Independence
B. Randomization
C. 10% Condition
D. Success/Failure Condition
E. Nearly Normal Condition
Copyright © 2009 Pearson Education, Inc.
Slide 18 - 5
A certain population is strongly skewed to the right.
We want to estimate its mean, so we will collect a
sample. Which should be true if we use a large
sample rather than a small one?
I.
The distribution of our sample data will be closer to
normal.
II. The sampling model of the sample means will be
closer to normal.
III. The variability of the sample means will be greater.
A. I only
B. II only
C. III only
D. I and III only
E. II and III only
Copyright © 2009 Pearson Education, Inc.
Slide 18 - 6
A certain population is strongly skewed to the right.
We want to estimate its mean, so we will collect a
sample. Which should be true if we use a large
sample rather than a small one?
I.
The distribution of our sample data will be closer to
normal.
II. The sampling model of the sample means will be
closer to normal.
III. The variability of the sample means will be greater.
A. I only
B. II only
C. III only
D. I and III only
E. II and III only
Copyright © 2009 Pearson Education, Inc.
Slide 18 - 7
It is generally believed that electrical
problems affect about 14% of new cars. An
automobile mechanic conducts diagnostic
tests on 128 new cars on the lot. How many
successes (electrical failures) do you
expect?
A. 1.28
B. 17.92
C. 110.08
D. Cannot determine from information given.
Copyright © 2009 Pearson Education, Inc.
Slide 18 - 8
It is generally believed that electrical
problems affect about 14% of new cars. An
automobile mechanic conducts diagnostic
tests on 128 new cars on the lot. How many
successes (electrical failures) do you
expect?
A. 1.28
B. 17.92
C. 110.08
D. Cannot determine from information given.
Copyright © 2009 Pearson Education, Inc.
Slide 18 - 9
Active Learning Lecture Slides
For use with Classroom Response Systems
Chapter 19:
Confidence Intervals for Proportions
Intro Stats
Third Edition
by De Veaux, Velleman, Bock
Copyright © 2009 Pearson Education, Inc.
Slide 19 - 10
The higher the level of confidence we want, the
narrower our confidence interval becomes.
A. True
B. False
Copyright © 2009 Pearson Education, Inc.
Slide 19 - 11
The higher the level of confidence we want, the
narrower our confidence interval becomes.
A. True
B. False
Copyright © 2009 Pearson Education, Inc.
Slide 19 - 12
The Success/Failure Condition states that we must
expect at least ____ “successes” and ____
“failures.”
A. 5
B. 10
C. 15
D. 25
Copyright © 2009 Pearson Education, Inc.
Slide 19 - 13
The Success/Failure Condition states that we must
expect at least ____ “successes” and ____
“failures.”
A. 5
B. 10
C. 15
D. 25
Copyright © 2009 Pearson Education, Inc.
Slide 19 - 14
We have calculated a 95% confidence interval and would
prefer for our next confidence interval to have a smaller
margin of error without losing any confidence. In order to
do this, we can
I. change the z∗ value to a smaller number.
II. take a larger sample.
III. take a smaller sample.
A. I only
B. II only
C. III only
D. I and II
E. I and III
Copyright © 2009 Pearson Education, Inc.
Slide 19 - 15
We have calculated a 95% confidence interval and would
prefer for our next confidence interval to have a smaller
margin of error without losing any confidence. In order to
do this, we can
I. change the z∗ value to a smaller number.
II. take a larger sample.
III. take a smaller sample.
A. I only
B. II only
C. III only
D. I and II
E. I and III
Copyright © 2009 Pearson Education, Inc.
Slide 19 - 16
Active Learning Lecture Slides
For use with Classroom Response Systems
Chapter 20:
Testing Hypotheses About Proportions
Intro Stats
Third Edition
by De Veaux, Velleman, Bock
Copyright © 2009 Pearson Education, Inc.
Slide 20 - 17
A P-value indicates
A. the probability that the null hypothesis is true.
B. the probability that the alternative hypothesis
is true.
C. the probability of the observed statistic given
that the null hypothesis is true.
D. the probability of the observed statistic given
that the alternative hypothesis is true.
Copyright © 2009 Pearson Education, Inc.
Slide 20 - 18
A P-value indicates
A. the probability that the null hypothesis is true.
B. the probability that the alternative hypothesis
is true.
C. the probability of the observed statistic given
that the null hypothesis is true.
D. the probability of the observed statistic given
that the alternative hypothesis is true.
Copyright © 2009 Pearson Education, Inc.
Slide 20 - 19
A small P-value indicates either that the
observation is improbable or that the probability
calculation was based on incorrect assumptions.
A. True
B. False
Copyright © 2009 Pearson Education, Inc.
Slide 20 - 20
A small P-value indicates either that the
observation is improbable or that the probability
calculation was based on incorrect assumptions.
A. True
B. False
Copyright © 2009 Pearson Education, Inc.
Slide 20 - 21
In a hypothesis test, the null hypothesis
represents the status quo.
A. True
B. False
Copyright © 2009 Pearson Education, Inc.
Slide 20 - 22
In a hypothesis test, the null hypothesis
represents the status quo.
A. True
B. False
Copyright © 2009 Pearson Education, Inc.
Slide 20 - 23
According to a June 2004 Gallup poll, 28% of
Americans “said there have been times in the last year
when they haven’t been able to afford medical care.” Is
this proportion higher for black Americans than for all
Americans? In a random sample of 801 black
Americans, 38% reported that there had been times in
the last year when they had not been able to afford
medical care. Which type of hypothesis test would you
use?
A. One-tail upper tail
B. One-tail lower tail
C. Two-tail
D. Both A and B
Copyright © 2009 Pearson Education, Inc.
Slide 20 - 24
According to a June 2004 Gallup poll, 28% of
Americans “said there have been times in the last year
when they haven’t been able to afford medical care.” Is
this proportion higher for black Americans than for all
Americans? In a random sample of 801 black
Americans, 38% reported that there had been times in
the last year when they had not been able to afford
medical care. Which type of hypothesis test would you
use?
A. One-tail upper tail
B. One-tail lower tail
C. Two-tail
D. Both A and B
Copyright © 2009 Pearson Education, Inc.
Slide 20 - 25
A statistics professor wants to see if more than 80% of
her students enjoyed taking her class. At the end of the
term, she takes a random sample of students from her
large class and asks, in an anonymous survey, if the
students enjoyed taking her class. Which set of
hypotheses should she test?
A. H0: p < 0.80 HA: p > 0.80
B. H0: p = 0.80 HA: p > 0.80
C. H0: p > 0.80 HA: p = 0.80
D. H0: p = 0.80 HA: p < 0.80
Copyright © 2009 Pearson Education, Inc.
Slide 20 - 26
A statistics professor wants to see if more than 80% of
her students enjoyed taking her class. At the end of the
term, she takes a random sample of students from her
large class and asks, in an anonymous survey, if the
students enjoyed taking her class. Which set of
hypotheses should she test?
A. H0: p < 0.80 HA: p > 0.80
B. H0: p = 0.80 HA: p > 0.80
C. H0: p > 0.80 HA: p = 0.80
D. H0: p = 0.80 HA: p < 0.80
Copyright © 2009 Pearson Education, Inc.
Slide 20 - 27
Active Learning Lecture Slides
For use with Classroom Response Systems
Chapter 22:
Comparing Two Proportions
Intro Stats
Third Edition
by De Veaux, Velleman, Bock
Copyright © 2009 Pearson Education, Inc.
Slide 22 - 28
When testing the difference between two proportions,
we need to check the Success/Failure Condition. Which
of the following is true?
I.
If only the smaller sample passes the Success/Failure Condition, we
can proceed with the test.
II.
If only the larger sample passes the Success/Failure Condition, we
can proceed with the test.
III. Both samples must pass the Success/Failure Condition to proceed
with the test.
A.
I only
B.
II only
C.
III only
D.
None of the above.
Copyright © 2009 Pearson Education, Inc.
Slide 22 - 29
When testing the difference between two proportions,
we need to check the Success/Failure Condition. Which
of the following is true?
I.
If only the smaller sample passes the Success/Failure
Condition, we can proceed with the test.
II. If only the larger sample passes the Success/Failure
Condition, we can proceed with the test.
III. Both samples must pass the Success/Failure Condition to
proceed with the test.
A.
I only
B.
II only
C.
III only
D.
None of the above.
Copyright © 2009 Pearson Education, Inc.
Slide 22 - 30
Active Learning Lecture Slides
For use with Classroom Response Systems
Chapter 23:
Inferences About Means
Intro Stats
Third Edition
by De Veaux, Velleman, Bock
Copyright © 2009 Pearson Education, Inc.
Slide 23 - 31
Which of the following is not an assumption or
condition that needs to be checked for a onesample t-test done on a sample drawn without
replacement?
A. Randomization
B. 10% Condition
C. Success/Failure Condition
D. Nearly Normal Condition
Copyright © 2009 Pearson Education, Inc.
Slide 23 - 32
Which of the following is not an assumption or
condition that needs to be checked for a onesample t-test done on a sample drawn without
replacement?
A. Randomization
B. 10% Condition
C. Success/Failure Condition
D. Nearly Normal Condition
Copyright © 2009 Pearson Education, Inc.
Slide 23 - 33
Which statement correctly compares t-distributions to the
normal distribution?
I. t distributions are also mound shaped and symmetric.
II. t distributions have less spread than the normal
distribution.
III. As degrees of freedom increase, the variance of tdistributions becomes smaller.
A. I only
B. II only
C. I and II only
D. I and III only
Copyright © 2009 Pearson Education, Inc.
Slide 23 - 34
Which statement correctly compares t-distributions to the
normal distribution?
I. t distributions are also mound shaped and symmetric.
II. t distributions have less spread than the normal
distribution.
III. As degrees of freedom increase, the variance of tdistributions becomes smaller.
A. I only
B. II only
C. I and II only
D. I and III only
Copyright © 2009 Pearson Education, Inc.
Slide 23 - 35
Which of the following is true about
Student’s t-models?
A. They are unimodal, symmetric, and bell
shaped.
B. They have fatter tails than the Normal
model.
C. As the degrees of freedom increase, the tmodels look more and more like the Normal
Model
D. All of the above.
Copyright © 2009 Pearson Education, Inc.
Slide 23 - 36
Which of the following is true about
Student’s t-models?
A. They are unimodal, symmetric, and bell
shaped.
B. They have fatter tails than the Normal
model.
C. As the degrees of freedom increase, the tmodels look more and more like the Normal
Model
D. All of the above.
Copyright © 2009 Pearson Education, Inc.
Slide 23 - 37
A researcher found that a 98% confidence interval
for the mean hours per week spent studying by
college students was (13, 17). Which is true?
A. There is a 98% chance that the mean hours per
week spent studying by college students is between
13 and 17 hours.
B. We are 98% sure that the mean hours per week
spent studying by college students is between 13
and 17 hours.
C. Students average between 13 and 17 hours per
week studying on 98% of the weeks.
D. 98% of all students spend between 13 and 17 hours
studying per week.
Copyright © 2009 Pearson Education, Inc.
Slide 23 - 38
A researcher found that a 98% confidence interval
for the mean hours per week spent studying by
college students was (13, 17). Which is true?
A. There is a 98% chance that the mean hours per
week spent studying by college students is between
13 and 17 hours.
B. We are 98% sure that the mean hours per week
spent studying by college students is between 13
and 17 hours.
C. Students average between 13 and 17 hours per
week studying on 98% of the weeks.
D. 98% of all students spend between 13 and 17 hours
studying per week.
Copyright © 2009 Pearson Education, Inc.
Slide 23 - 39
A philosophy professor wants to find out whether the mean age of the
men in his large lecture class is equal to the mean age of the women
in his class. After collecting data from his students, the professor
tested the hypothesis against the alternative
.
The P-value for the test was 0.003. Which is true?
H0 : M - W = 0
HA : M - W  0
A. There is a 0.3% chance that the mean age for the men is equal to
the mean age for the women.
B. There is a 0.3% chance that the mean age for the men is different
from the mean age of the women.
C. It is very unlikely that the professor would see results like these if
the mean age of men was equal to the mean age of women.
D. There is a 0.3% chance that another sample will give these same
results.
Copyright © 2009 Pearson Education, Inc.
Slide 24 - 40
A philosophy professor wants to find out whether the mean
age of the men in his large lecture class is equal to the
mean age of the women in his class. After collecting data
from his students, the professor tested the hypothesis
against the alternative. The P-value for the test was
0.003. Which is true?
HA : M - W ­ 0
H0 : M - W = 0
A. There is a 0.3% chance that the mean age for the men is equal to
the mean age for the women.
B. There is a 0.3% chance that the mean age for the men is different
from the mean age of the women.
C. It is very unlikely that the professor would see results like these if
the mean age of men was equal to the mean age of women.
D. There is a 0.3% chance that another sample will give these same
results.
Copyright © 2009 Pearson Education, Inc.
Slide 24 - 41
Doctors at a technology research facility randomly assigned equal numbers of
people to use computer keyboards in two rooms. In one room a group of
people typed a manuscript using standard keyboards, while in the other room
people typed the same manuscript using ergonomic keyboards to see if those
people could type more words per minute. After collecting data for several
days the researchers tested the hypothesis against the one-tail alternative and
found a P-value of 0.22. Which is true?
H0 : 1 - 2 = 0
A) The people using ergonomic keyboards type 22% more words per
minute.
B) There’s a 22% chance that people using ergonomic keyboards
type more words per minute.
C) There’s a 22% chance that there’s really no difference in typing
speed.
D) There’s a 22% chance another experiment will give these same
results.
E) None of these.
Copyright © 2009 Pearson Education, Inc.
Slide 24 - 42
Doctors at a technology research facility randomly assigned equal numbers of
people to use computer keyboards in two rooms. In one room a group of
people typed a manuscript using standard keyboards, while in the other room
people typed the same manuscript using ergonomic keyboards to see if those
people could type more words per minute. After collecting data for several
days the researchers tested the hypothesis against the one-tail alternative and
found a P-value of 0.22. Which is true?
H0 : 1 - 2 = 0
A) The people using ergonomic keyboards type 22% more words per
minute.
B) There’s a 22% chance that people using ergonomic keyboards
type more words per minute.
C) There’s a 22% chance that there’s really no difference in typing
speed.
D) There’s a 22% chance another experiment will give these same
results.
E) None of these.
Copyright © 2009 Pearson Education, Inc.
Slide 24 - 43
Trainers need to estimate the level of fat in athletes to
ensure good health. Initial tests were based on a small
sample but now the trainers double the sample size for a
follow-up test. The main purpose of the larger sample is
to…
A. reduce response bias.
B. reduce non-response bias.
C. decrease the variability in the population.
D. reduce confounding due to other variables.
E. decrease the standard deviation of the sampling
model.
Copyright © 2009 Pearson Education, Inc.
Slide 24 - 44
Trainers need to estimate the level of fat in athletes to
ensure good health. Initial tests were based on a small
sample but now the trainers double the sample size for a
follow-up test. The main purpose of the larger sample is
to…
A. reduce response bias.
B. reduce non-response bias.
C. decrease the variability in the population.
D. reduce confounding due to other variables.
E. decrease the standard deviation of the sampling
model.
Copyright © 2009 Pearson Education, Inc.
Slide 24 - 45