Transcript Active Learning Lecture Slides For use with

Active Learning Lecture Slides
For use with Classroom Response Systems
Statistical Inference: Confidence Intervals
8.1 A good point estimate has which of the
following characteristics?
a) Bias: None
b) Bias: High
c) Bias: None
d) Bias: High
Copyright © 2013 Pearson Education, Inc.
Standard Error: High
Standard Error: High
Standard Error: Low
Standard Error: Low
8.1 A good point estimate has which of the
following characteristics?
a) Bias: None
b) Bias: High
c) Bias: None
d) Bias: High
Copyright © 2013 Pearson Education, Inc.
Standard Error: High
Standard Error: High
Standard Error: Low
Standard Error: Low
8.2 When the sampling distribution is
approximately normal, what is the margin of error
equal to for a 95% confidence interval?
a) 1.96
b) 1.96*standard error
c) Standard error
d) Point estimate  1.96*standard error
Copyright © 2013 Pearson Education, Inc.
8.2 When the sampling distribution is
approximately normal, what is the margin of error
equal to for a 95% confidence interval?
a) 1.96
b) 1.96*standard error
c) Standard error
d) Point estimate  1.96*standard error
Copyright © 2013 Pearson Education, Inc.
8.3 In 2006 the GSS had a special topic that
investigated disabilities. They asked respondents if
they had difficulty fully participating in school,
housework or other daily activities and 265 out of
2,749 said “yes”. What is the point estimate of the
population proportion of Americans that have
difficulty completing these tasks?
a) 0.10
b) 0.097
c) 0.265
d) p
e) Unknown
Copyright © 2013 Pearson Education, Inc.
8.3 In 2006 the GSS had a special topic that
investigated disabilities. They asked respondents if
they had difficulty fully participating in school,
housework or other daily activities and 265 out of
2,749 said “yes”. What is the point estimate of the
population proportion of Americans that have
difficulty completing these tasks?
a) 0.10
b) 0.097
c) 0.265
d) p
e) Unknown
Copyright © 2013 Pearson Education, Inc.
8.4 True or False: A point estimate is better than
an interval estimate because it gives you the exact
value for which you are looking.
a) True
b) False
Copyright © 2013 Pearson Education, Inc.
8.4 True or False: A point estimate is better than
an interval estimate because it gives you the exact
value for which you are looking.
a) True
b) False
Copyright © 2013 Pearson Education, Inc.
8.5 True or False: An interval estimate gives you a
region that the parameter has to fall within.
a) True
b) False
Copyright © 2013 Pearson Education, Inc.
8.5 True or False: An interval estimate gives you a
region that the parameter has to fall within.
a) True
b) False
Copyright © 2013 Pearson Education, Inc.
8.6 The formula below gives a region of plausible
values of :
pˆ  z
pˆ 1  pˆ 
n
a) the population proportion
b) the population mean
c) the sample mean
d) the sample proportion
Copyright © 2013 Pearson Education, Inc.
8.6 The formula below gives a region of plausible
values of :
pˆ  z
pˆ 1  pˆ 
n
a) the population proportion
b) the population mean
c) the sample mean
d) the sample proportion
Copyright © 2013 Pearson Education, Inc.
8.7 In 2006 the GSS asked 2,986 people if they were
very happy, pretty happy, or not too happy and 920
people said that they were very happy. Is the sample
“large” enough to calculate the 95% confidence
interval to estimate the proportion of all Americans that
are very happy?
a) Yes, there are more than 30 observations.
b) Yes, there are more than 15 successes and 15
failures.
c) No, there are not more than 15 successes and 15
failures.
d) Cannot be determined.
Copyright © 2013 Pearson Education, Inc.
8.7 In 2006 the GSS asked 2,986 people if they were
very happy, pretty happy, or not too happy and 920
people said that they were very happy. Is the sample
“large” enough to calculate the 95% confidence
interval to estimate the proportion of all Americans that
are very happy?
a) Yes, there are more than 30 observations.
b) Yes, there are more than 15 successes and 15
failures.
c) No, there are not more than 15 successes and 15
failures.
d) Cannot be determined.
Copyright © 2013 Pearson Education, Inc.
8.8 In 2006 the GSS asked 2,986 people if they
were very happy, pretty happy, or not too happy
and 920 people said that they were very happy.
Find the 95% confidence interval to estimate the
proportion of all Americans that are very happy.
a) (0, 0.02)
b) (0.25, 0.37)
c) (0.27, 0.35)
d) (0.29, 0.32)
Copyright © 2013 Pearson Education, Inc.
8.8 In 2006 the GSS asked 2,986 people if they
were very happy, pretty happy, or not too happy
and 920 people said that they were very happy.
Find the 95% confidence interval to estimate the
proportion of all Americans that are very happy.
a) (0, 0.02)
b) (0.25, 0.37)
c) (0.27, 0.35)
d) (0.29, 0.32)
Copyright © 2013 Pearson Education, Inc.
8.10 Based off of the same sample, which of the
confidence intervals for the population mean
would be the widest?
a) A 90% confidence interval
b) A 95% confidence interval
c) A 99% confidence interval
d) Cannot be determined
Copyright © 2013 Pearson Education, Inc.
8.10 Based off of the same sample, which of the
confidence intervals for the population mean
would be the widest?
a) A 90% confidence interval
b) A 95% confidence interval
c) A 99% confidence interval
d) Cannot be determined
Copyright © 2013 Pearson Education, Inc.
8.11 The margin of error of a confidence interval
of the population mean decreases as…
a) the sample size decreases.
b) the sample size increases.
c) the sample mean increases.
d) the sample mean decreases.
Copyright © 2013 Pearson Education, Inc.
8.11 The margin of error of a confidence interval
of the population mean decreases as…
a) the sample size decreases.
b) the sample size increases.
c) the sample mean increases.
d) the sample mean decreases.
Copyright © 2013 Pearson Education, Inc.
8.12 The General Social Survey included a
question about how many hours the respondent
spent doing religious activities outside of their own
home. For the 1,414 respondents the sample mean
was 6.15 hours and the sample standard deviation
was 16.53 hours. Find the 95% confidence interval
for the population mean amount of time spent doing
religious activities outside of their own home.
a) (5.43, 6.87)
b) (-26.24, 38.55)
c) (5.29, 7.01)
d) (5.03, 7.27)
Copyright © 2013 Pearson Education, Inc.
8.12 The General Social Survey included a
question about how many hours the respondent
spent doing religious activities outside of their own
home. For the 1,414 respondents the sample mean
was 6.15 hours and the sample standard deviation
was 16.53 hours. Find the 95% confidence interval
for the population mean amount of time spent doing
religious activities outside of their own home.
a) (5.43, 6.87)
b) (-26.24, 38.55)
c) (5.29, 7.01)
d) (5.03, 7.27)
Copyright © 2013 Pearson Education, Inc.
8.13 The General Social Survey included a
question about how many hours the respondent
spent doing religious activities outside of their own
home. For the 1,414 respondents the sample mean
was 6.15 hours and the sample standard deviation
was 16.53 hours. What can we say about the
distribution of hours spent doing religious
activities?
a) It is bell shaped.
b) It is right skewed.
c) It is left skewed.
d) Nothing can be determined.
Copyright © 2013 Pearson Education, Inc.
8.13 The General Social Survey included a
question about how many hours the respondent
spent doing religious activities outside of their own
home. For the 1,414 respondents the sample mean
was 6.15 hours and the sample standard deviation
was 16.53 hours. What can we say about the
distribution of hours spent doing religious
activities?
a) It is bell shaped.
b) It is right skewed.
c) It is left skewed.
d) Nothing can be determined.
Copyright © 2013 Pearson Education, Inc.
8.21 The margin of error of a confidence interval
estimates the error…
a) caused by bad sampling techniques.
b) caused by measurement error.
c) caused by not controlling lurking variables.
d) caused by using a sample rather than the whole
population.
e) all of the above.
Copyright © 2013 Pearson Education, Inc.
8.21 The margin of error of a confidence interval
estimates the error…
a) caused by bad sampling techniques.
b) caused by measurement error.
c) caused by not controlling lurking variables.
d) caused by using a sample rather than the whole
population.
e) all of the above.
Copyright © 2013 Pearson Education, Inc.