STAT 211 final exam With complete solution Newest
RATED A+ 2025/2026 NEW!!
Which of these statements correctly interprets what it means to be "95% confident"?
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
A. 95% of the sample is in the confidence interval.
Il` Il` Il` Il` Il` Il` Il` Il` Il`
B. 95% of samples will produce a confidence interval that captures the true proportion.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
C. 95% of the time, the sample proportion will be in the interval. -
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
Correct Answers B. 95% of samples will produce a confidence interval that captures the true prop
Il`Il` Il` Il`Il`Il`Il`Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
ortion.
Il` A research company polled a random sample of
Il` Il` Il` Il` Il` Il` Il` Il`
646 teens about Internet use 50
Il` Il` Il` Il` Il`
% of those teens reported that they had misrepresented their age online to gain access to websites
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
and online services. Il` Il` Il`
Explain the meaning of p^=0.50 in the context of this situation.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
A. The meaning of p=0.50 is that the researchers have 95% confidence that 50
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
% of all U.S. teens would say that they have misrepresented their age online.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
B. The meaning of p=0.50 is that the researchers have 95% confidence that 50
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
% of the 646 teens in the sample said they have misrepresented their age online.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
C. The meaning of p=0.50 is that 50
Il` Il` Il` Il` Il` Il` Il`
% of the 646 teens in the sample said they have misrepresented their age online. This is the
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
researchers' best estimate of p, the proportion of all U.S. teens who would say they have done so.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
D. The meaning of p=0.50 is that 50
Il` Il` Il` Il` Il` Il` Il`
% of the 646 teens in the sample said they have misrepresented their age online. This -
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
Correct Answers C. The meaning of p=0.50 is that 50
Il`Il` Il` Il`Il`Il`Il`Il` Il` Il` Il` Il` Il` Il` Il`
% of the 646 teens in the sample said they have misrepresented their age online. This is the
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
researchers' best estimate of p, the proportion of all U.S. teens who would say they have done so.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
Il` A research company polled a random sample of
Il` Il` Il` Il` Il` Il` Il` Il`
,646 teens about Internet use 50 Il` Il` Il` Il` Il`
% of those teens reported that they had misrepresented their age online to gain access to websites
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
and online services. SE (P^) = .020 Explain what this standard error means in the context of this situa
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
tion.
A. The standard error is the best estimate of the margin of error of the poll. The researchers can be c
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
onfident that the difference between p and p is not greater than the standard error. Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
B. The standard error is the best estimate of the standard deviation of the sampling distribution of t
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
he
proportions, which measures the amount of variation in the sample and population proportions.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
C. The standard error is the best estimate of the standard deviation of the sampling distribution of t
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
he
proportions, which measures the amount of variation in the sample proportion expected to be see
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
n from sample to sample when 646 teens are asked the po -
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
Correct Answers C. The standard error is the best estimate of the standard deviation of the sampli
Il`Il` Il` Il`Il`Il`Il`Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
ng distribution of the Il` Il` Il`
proportions, which measures the amount of variation in the sample proportion expected to be see
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
n from sample to sample when 646 teens are asked the polling question.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
Il` Reaching out 2 standard errors on either side of the sample proportion makes us Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
Il` __________ confident that the true proportion is captured within the interval. - Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
Il`Il`Correct Answers 95% Il` Il`Il`Il`Il`Il`
Of 575 broiler chickens purchased from various kinds of food stores in different regions of a country
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il
and tested for types of bacteria that cause food-borne illnesses, 36
` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
% were infected with a particular bacterium. 95% CI = 32.1% -
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
39.9% What does the confidence interval say about chicken sold in the country?
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
A. There is a 95 Il` Il` Il` Il`
% chance that the true proportion of broiler chickens infected with the bacterium is in the interval.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
B. In 95% of samples of broiler chickens sold in the
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
country, the proportion infected with the bacterium will be in the interval.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
C. We are 95 Il` Il` Il`
% confident that the interval captures the true proportion of all broiler chickens sold in the country t
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
hat are infected with the bacterium. - Correct Answers C. We are 95
Il` Il` Il` Il` Il` Il` Il`Il` Il` Il`Il`Il`Il`Il` Il` Il` Il`
, % confident that the interval captures the true proportion of all broiler chickens sold in the country t
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
hat are infected with the bacterium.
Il` Il` Il` Il` Il`
Of 575 broiler chickens purchased from various kinds of food stores in different regions of a country
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il
and tested for types of bacteria that cause food-borne illnesses, 36
` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
% were infected with a particular bacterium. A government spokesperson claimed that the sample
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
size was too small, relative to the billions of chickens slaughtered each
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
year, to generalize. Is this criticism valid?
Il` Il` Il` Il` Il` Il` Il`
A. Yes, the sample size must be at least 10% of the population, or the results cannot be generalized.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
B. No, as long as the necessary assumptions and conditions were
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
met, the results can be generalized.
Il` Il` Il` Il` Il` Il`
C. Yes, until another study produces a similar interval, the results cannot be generalized. -
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
Correct Answers B. No, as long as the necessary assumptions and conditions were
Il`Il` Il` Il`Il`Il`Il`Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
met, the results can be generalized.
Il` Il` Il` Il` Il` Il`
A polling company conducts an annual poll of adults about political opinions. The survey asked a ra
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
ndom sample of 473 adults whether they think things in the country are going in the right direction
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
or in the wrong direction 71
Il` Il` Il` Il` Il`
% said that things were going in the wrong direction. ME = .041. Would the margin of error be larger
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
or smaller for 99% confidence? Explain.
Il` Il` Il` Il` Il`
A. To be more confident, the interval needs to contain the true proportion less often, so the margin
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
of error would be smaller.
Il` Il` Il` Il`
B. To be more confident, the interval needs to contain the true proportion more often, so the margi
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
n of error would be larger.
Il` Il` Il` Il` Il`
C. To be more confident, the interval needs to contain the true proportion more often, so the margi
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
n of error would be smaller.
Il` Il` Il` Il` Il`
D. To be more confident, the interval needs to contain the true proportion less often, so the margin
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
of error would be larger. -
Il` Il` Il` Il` Il`
Correct Answers B. To be more confident, the interval needs to contain the true proportion more
Il`Il` Il` Il`Il`Il`Il`Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
often, so the margin of error would be larger. Il` Il` Il` Il` Il` Il` Il` Il`
RATED A+ 2025/2026 NEW!!
Which of these statements correctly interprets what it means to be "95% confident"?
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
A. 95% of the sample is in the confidence interval.
Il` Il` Il` Il` Il` Il` Il` Il` Il`
B. 95% of samples will produce a confidence interval that captures the true proportion.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
C. 95% of the time, the sample proportion will be in the interval. -
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
Correct Answers B. 95% of samples will produce a confidence interval that captures the true prop
Il`Il` Il` Il`Il`Il`Il`Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
ortion.
Il` A research company polled a random sample of
Il` Il` Il` Il` Il` Il` Il` Il`
646 teens about Internet use 50
Il` Il` Il` Il` Il`
% of those teens reported that they had misrepresented their age online to gain access to websites
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
and online services. Il` Il` Il`
Explain the meaning of p^=0.50 in the context of this situation.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
A. The meaning of p=0.50 is that the researchers have 95% confidence that 50
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
% of all U.S. teens would say that they have misrepresented their age online.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
B. The meaning of p=0.50 is that the researchers have 95% confidence that 50
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
% of the 646 teens in the sample said they have misrepresented their age online.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
C. The meaning of p=0.50 is that 50
Il` Il` Il` Il` Il` Il` Il`
% of the 646 teens in the sample said they have misrepresented their age online. This is the
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
researchers' best estimate of p, the proportion of all U.S. teens who would say they have done so.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
D. The meaning of p=0.50 is that 50
Il` Il` Il` Il` Il` Il` Il`
% of the 646 teens in the sample said they have misrepresented their age online. This -
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
Correct Answers C. The meaning of p=0.50 is that 50
Il`Il` Il` Il`Il`Il`Il`Il` Il` Il` Il` Il` Il` Il` Il`
% of the 646 teens in the sample said they have misrepresented their age online. This is the
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
researchers' best estimate of p, the proportion of all U.S. teens who would say they have done so.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
Il` A research company polled a random sample of
Il` Il` Il` Il` Il` Il` Il` Il`
,646 teens about Internet use 50 Il` Il` Il` Il` Il`
% of those teens reported that they had misrepresented their age online to gain access to websites
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
and online services. SE (P^) = .020 Explain what this standard error means in the context of this situa
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
tion.
A. The standard error is the best estimate of the margin of error of the poll. The researchers can be c
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
onfident that the difference between p and p is not greater than the standard error. Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
B. The standard error is the best estimate of the standard deviation of the sampling distribution of t
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
he
proportions, which measures the amount of variation in the sample and population proportions.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
C. The standard error is the best estimate of the standard deviation of the sampling distribution of t
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
he
proportions, which measures the amount of variation in the sample proportion expected to be see
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
n from sample to sample when 646 teens are asked the po -
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
Correct Answers C. The standard error is the best estimate of the standard deviation of the sampli
Il`Il` Il` Il`Il`Il`Il`Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
ng distribution of the Il` Il` Il`
proportions, which measures the amount of variation in the sample proportion expected to be see
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
n from sample to sample when 646 teens are asked the polling question.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
Il` Reaching out 2 standard errors on either side of the sample proportion makes us Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
Il` __________ confident that the true proportion is captured within the interval. - Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
Il`Il`Correct Answers 95% Il` Il`Il`Il`Il`Il`
Of 575 broiler chickens purchased from various kinds of food stores in different regions of a country
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il
and tested for types of bacteria that cause food-borne illnesses, 36
` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
% were infected with a particular bacterium. 95% CI = 32.1% -
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
39.9% What does the confidence interval say about chicken sold in the country?
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
A. There is a 95 Il` Il` Il` Il`
% chance that the true proportion of broiler chickens infected with the bacterium is in the interval.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
B. In 95% of samples of broiler chickens sold in the
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
country, the proportion infected with the bacterium will be in the interval.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
C. We are 95 Il` Il` Il`
% confident that the interval captures the true proportion of all broiler chickens sold in the country t
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
hat are infected with the bacterium. - Correct Answers C. We are 95
Il` Il` Il` Il` Il` Il` Il`Il` Il` Il`Il`Il`Il`Il` Il` Il` Il`
, % confident that the interval captures the true proportion of all broiler chickens sold in the country t
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
hat are infected with the bacterium.
Il` Il` Il` Il` Il`
Of 575 broiler chickens purchased from various kinds of food stores in different regions of a country
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il
and tested for types of bacteria that cause food-borne illnesses, 36
` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
% were infected with a particular bacterium. A government spokesperson claimed that the sample
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
size was too small, relative to the billions of chickens slaughtered each
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
year, to generalize. Is this criticism valid?
Il` Il` Il` Il` Il` Il` Il`
A. Yes, the sample size must be at least 10% of the population, or the results cannot be generalized.
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
B. No, as long as the necessary assumptions and conditions were
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
met, the results can be generalized.
Il` Il` Il` Il` Il` Il`
C. Yes, until another study produces a similar interval, the results cannot be generalized. -
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
Correct Answers B. No, as long as the necessary assumptions and conditions were
Il`Il` Il` Il`Il`Il`Il`Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
met, the results can be generalized.
Il` Il` Il` Il` Il` Il`
A polling company conducts an annual poll of adults about political opinions. The survey asked a ra
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
ndom sample of 473 adults whether they think things in the country are going in the right direction
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
or in the wrong direction 71
Il` Il` Il` Il` Il`
% said that things were going in the wrong direction. ME = .041. Would the margin of error be larger
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
or smaller for 99% confidence? Explain.
Il` Il` Il` Il` Il`
A. To be more confident, the interval needs to contain the true proportion less often, so the margin
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
of error would be smaller.
Il` Il` Il` Il`
B. To be more confident, the interval needs to contain the true proportion more often, so the margi
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
n of error would be larger.
Il` Il` Il` Il` Il`
C. To be more confident, the interval needs to contain the true proportion more often, so the margi
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
n of error would be smaller.
Il` Il` Il` Il` Il`
D. To be more confident, the interval needs to contain the true proportion less often, so the margin
Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
of error would be larger. -
Il` Il` Il` Il` Il`
Correct Answers B. To be more confident, the interval needs to contain the true proportion more
Il`Il` Il` Il`Il`Il`Il`Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il` Il`
often, so the margin of error would be larger. Il` Il` Il` Il` Il` Il` Il` Il`
