Stat Test Practice Test 4 EXAM
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The difference between teenage female and male depression rates estimated from
two samples is 0.08. The estimated standard error of the sampling distribution is
0.04. What is the 95% confidence interval? Use the critical value z = 1.96.
(, )
Round all calculations to two decimal places. Put lower bound in the first box and
upper bound in the second box. - ANSWER ✓ 0.00,.16
Quit Smoking: Previous studies suggest that use of nicotine-replacement therapies
and antidepressants can help people stop smoking. The New England Journal of
Medicine published the results of a double-blind, placebo-controlled experiment to
study the effect of nicotine patches and the antidepressant bupropion on quitting
smoking. The target for quitting smoking was the 8th day of the experiment.
In this experiment researchers randomly assigned smokers to treatments. Of the
162 smokers taking a placebo, 31 stopped smoking by the 8th day. Of the 256
smokers taking only the antidepressant buproprion, 81 stopped smoking by the 8th
day. Calculate the estimated standard error for the sampling distribution of
differences in sample proportions.
The estimated standard error = - ANSWER ✓
Quit Smoking: Previous studies suggest that use of nicotine-replacement therapies
and antidepressants can help people stop smoking. The New England Journal of
Medicine published the results of a double-blind, placebo-controlled experiment to
study the effect of nicotine patches and the antidepressant bupropion on quitting
smoking. The target for quitting smoking was the 8th day of the experiment.
In this experiment researchers randomly assigned smokers to treatments. Of the
162 smokers taking a placebo, 28 stopped smoking by the 8th day. Of the 272
,smokers taking only the antidepressant buproprion, 82 stopped smoking by the 8th
day.
Calculate the 99% confidence interval to estimate the treatment effect of
buproprion (placebo-treatment). (The standard error is about 0.0407. Use critical
value z = 2.576.)
(, ) - ANSWER ✓
Gardeners on the west coast of the United States are investigating the difference in
survival rates of two flowering plants in drought climates. Plant A has a survival
rate of 0.6 and plant B has a survival rate of 0.43. The standard error of the
difference in proportions is 0.084. What is the margin of error for a 99%
confidence interval? Use critical value z = 2.576.
MOE = - ANSWER ✓ .216
The 99% confidence interval for the difference in proportions of women and men
who support stricter gun control is (0.02, 0.08). (Difference here is "women" minus
"men.") Which of the following conclusions about the confidence interval is most
appropriate? - ANSWER ✓ We are 99% confident that the difference between the
proportions of women and men who support stricter gun control is between 0.02
and 0.08.
In 2011, the Institute of Medicine (IOM), a non-profit group affiliated with the US
National Academy of Sciences, reviewed a study measuring bone quality and
levels of vitamin-D in a random sample from bodies of 675 people who died in
good health. 8.5% of the 82 bodies with low vitamin-D levels (below 50 nmol/L)
had weak bones. Comparatively, 1% of the 593 bodies with regular vitamin-D
levels had weak bones.
Is a normal model a good fit for the sampling distribution? - ANSWER ✓
Researchers conducted a randomized, double-blind clinical trial to compare the
herb St. John's Wort, the antidepressant drug sertraline, and a placebo for the
treatment of depression. Of the 113 patients in the herb treatment group, 23.9%
showed improvement, compared to 24.8% of the 113 in the sertraline group and
31.9% of the 113 patients in the placebo group. Medscape Medical News
published this research in 2002.
Is a normal model a good fit for the sampling distribution? - ANSWER ✓ Yes,
there are at least 10 people who improved and 10 who did not improve in each
randomized treatment group.
, Students in a discussion of gun control in a sociology class at Foothill Community
College argue that Republicans are more likely to oppose gun control than
Independents. They use data from an article titled "Gun Control Splits America,"
published March 23, 2010 in pewresarch.org by the Pew Research Center for the
People and the Press. In this study 62% of Republicans and 57% of Independents
say that states should not be able to pass laws banning handguns.
The article states that researchers collected data from 1,500 adults nationwide
reached on landlines and cell phones. Which issue will invalidate the conclusion of
the hypothesis test? - ANSWER ✓ The data is not a random sample. maybe??
A politician claims that a larger proportion of members of the news media are
Democrats when compared to the general public. Let p1 represent the proportion of
the news media that is Democrat and p2 represent the proportion of the public that
is Democrat. What are the appropriate null and alternative hypotheses that
correspond to this claim? - ANSWER ✓ H0: p1 - p2 = 0; Ha: p1 - p2 > 0
A scientist claims that a smaller proportion of members of the National Academy
of Sciences are women when compared to the proportion of women nationwide.
Let p1 represent the proportion of women in the National Academy of Sciences
and p2 represent the proportion of women nationwide. Which is the correct
alternative hypotheses that corresponds to this claim? - ANSWER ✓ Ha: p1 - p2 <
0
In the article "Attitudes About Marijuana and Political Views" (Psychological
Reports, 1973), researchers reported on the use of cannabis by liberals and
conservatives during the 1970s.
To test the claim (at 1% significance) that the proportion of voters who smoked
cannabis frequently was lower among conservatives, the hypotheses were
In this hypothesis test which of the following errors is a Type II error? - ANSWER
✓ We conclude that there is no difference between the proportions of conservatives
and liberals that smoke cannabis, when the proportion is actually lower for
conservatives.
In the article Foods, Fortificants, and Supplements: Where Do Americans Get
Their Nutrients? researchers analyze the nutrient and vitamin intake from a random
sample of 16,110 U.S. residents. Researchers compare the level of daily vitamin
intake for vitamin A, vitamin B-6, vitamin B-12, vitamin C, vitamin D, vitamin E
REVIEW WITH EXAM QUESTIONS
AND CORRECT SOLUTIONS A+
GRADED UPDATED 2025/2026||100%
GUARANTEED PASS!!<<LATEST
EXAM>>
The difference between teenage female and male depression rates estimated from
two samples is 0.08. The estimated standard error of the sampling distribution is
0.04. What is the 95% confidence interval? Use the critical value z = 1.96.
(, )
Round all calculations to two decimal places. Put lower bound in the first box and
upper bound in the second box. - ANSWER ✓ 0.00,.16
Quit Smoking: Previous studies suggest that use of nicotine-replacement therapies
and antidepressants can help people stop smoking. The New England Journal of
Medicine published the results of a double-blind, placebo-controlled experiment to
study the effect of nicotine patches and the antidepressant bupropion on quitting
smoking. The target for quitting smoking was the 8th day of the experiment.
In this experiment researchers randomly assigned smokers to treatments. Of the
162 smokers taking a placebo, 31 stopped smoking by the 8th day. Of the 256
smokers taking only the antidepressant buproprion, 81 stopped smoking by the 8th
day. Calculate the estimated standard error for the sampling distribution of
differences in sample proportions.
The estimated standard error = - ANSWER ✓
Quit Smoking: Previous studies suggest that use of nicotine-replacement therapies
and antidepressants can help people stop smoking. The New England Journal of
Medicine published the results of a double-blind, placebo-controlled experiment to
study the effect of nicotine patches and the antidepressant bupropion on quitting
smoking. The target for quitting smoking was the 8th day of the experiment.
In this experiment researchers randomly assigned smokers to treatments. Of the
162 smokers taking a placebo, 28 stopped smoking by the 8th day. Of the 272
,smokers taking only the antidepressant buproprion, 82 stopped smoking by the 8th
day.
Calculate the 99% confidence interval to estimate the treatment effect of
buproprion (placebo-treatment). (The standard error is about 0.0407. Use critical
value z = 2.576.)
(, ) - ANSWER ✓
Gardeners on the west coast of the United States are investigating the difference in
survival rates of two flowering plants in drought climates. Plant A has a survival
rate of 0.6 and plant B has a survival rate of 0.43. The standard error of the
difference in proportions is 0.084. What is the margin of error for a 99%
confidence interval? Use critical value z = 2.576.
MOE = - ANSWER ✓ .216
The 99% confidence interval for the difference in proportions of women and men
who support stricter gun control is (0.02, 0.08). (Difference here is "women" minus
"men.") Which of the following conclusions about the confidence interval is most
appropriate? - ANSWER ✓ We are 99% confident that the difference between the
proportions of women and men who support stricter gun control is between 0.02
and 0.08.
In 2011, the Institute of Medicine (IOM), a non-profit group affiliated with the US
National Academy of Sciences, reviewed a study measuring bone quality and
levels of vitamin-D in a random sample from bodies of 675 people who died in
good health. 8.5% of the 82 bodies with low vitamin-D levels (below 50 nmol/L)
had weak bones. Comparatively, 1% of the 593 bodies with regular vitamin-D
levels had weak bones.
Is a normal model a good fit for the sampling distribution? - ANSWER ✓
Researchers conducted a randomized, double-blind clinical trial to compare the
herb St. John's Wort, the antidepressant drug sertraline, and a placebo for the
treatment of depression. Of the 113 patients in the herb treatment group, 23.9%
showed improvement, compared to 24.8% of the 113 in the sertraline group and
31.9% of the 113 patients in the placebo group. Medscape Medical News
published this research in 2002.
Is a normal model a good fit for the sampling distribution? - ANSWER ✓ Yes,
there are at least 10 people who improved and 10 who did not improve in each
randomized treatment group.
, Students in a discussion of gun control in a sociology class at Foothill Community
College argue that Republicans are more likely to oppose gun control than
Independents. They use data from an article titled "Gun Control Splits America,"
published March 23, 2010 in pewresarch.org by the Pew Research Center for the
People and the Press. In this study 62% of Republicans and 57% of Independents
say that states should not be able to pass laws banning handguns.
The article states that researchers collected data from 1,500 adults nationwide
reached on landlines and cell phones. Which issue will invalidate the conclusion of
the hypothesis test? - ANSWER ✓ The data is not a random sample. maybe??
A politician claims that a larger proportion of members of the news media are
Democrats when compared to the general public. Let p1 represent the proportion of
the news media that is Democrat and p2 represent the proportion of the public that
is Democrat. What are the appropriate null and alternative hypotheses that
correspond to this claim? - ANSWER ✓ H0: p1 - p2 = 0; Ha: p1 - p2 > 0
A scientist claims that a smaller proportion of members of the National Academy
of Sciences are women when compared to the proportion of women nationwide.
Let p1 represent the proportion of women in the National Academy of Sciences
and p2 represent the proportion of women nationwide. Which is the correct
alternative hypotheses that corresponds to this claim? - ANSWER ✓ Ha: p1 - p2 <
0
In the article "Attitudes About Marijuana and Political Views" (Psychological
Reports, 1973), researchers reported on the use of cannabis by liberals and
conservatives during the 1970s.
To test the claim (at 1% significance) that the proportion of voters who smoked
cannabis frequently was lower among conservatives, the hypotheses were
In this hypothesis test which of the following errors is a Type II error? - ANSWER
✓ We conclude that there is no difference between the proportions of conservatives
and liberals that smoke cannabis, when the proportion is actually lower for
conservatives.
In the article Foods, Fortificants, and Supplements: Where Do Americans Get
Their Nutrients? researchers analyze the nutrient and vitamin intake from a random
sample of 16,110 U.S. residents. Researchers compare the level of daily vitamin
intake for vitamin A, vitamin B-6, vitamin B-12, vitamin C, vitamin D, vitamin E
