Here are summary statistics for randomly selected weights of newborn girls:
n=237,
x=29.4
hg,
s=7.1
- Construct a confidence interval estimate of the mean. Use a
90%
confidence level. Are these results very different from the confidence interval
28.2
hg<><>
hg with only
12
sample values,
x=29.7
hg, and
s=2.8
hg?
What is the confidence interval for the population mean
μ?
nothing
hg<><>
hg (Round to one decimal place as needed.)
Are the results between the two confidence intervals very different?
A.
Yes, because one confidence interval does not contain the mean of the other confidence interval.
B.
No, because each confidence interval contains the mean of the other confidence interval.
C.
Yes, because the confidence interval limits are not similar.
D.
No, because the confidence interval limits are similar.
An online poll asked: "Do you believe the Loch Ness monster exists?" Among
20,294
responses,
64%
were "yes." Use a
0.05
significance level to test the claim that most people believe that the Loch Ness monster exists. How is the conclusion affected by the fact that Internet users who saw the question could decide whether to respond?
Identify the null and alternative hypotheses for this test. Choose the correct answer below.
A.
H0:
p>0.5
H1:
p=0.5
B.
H0:
p=0.5
H1:
p<>
C.
H0:
p=0.5
H1:
p>0.5
D.
H0:
p=0.5
H1:
p≠0.5
Identify the test statistic for this hypothesis test.
The test statistic for this hypothesis test is
nothing.
(Round to two decimal places as needed.)
Identify the P-value for this hypothesis test.
The P-value for this hypothesis test is
nothing.
(Round to three decimal places as needed.)
Identify the conclusion for this hypothesis test.
A.
Reject
H0.
There
is not
sufficient evidence to warrant rejection of the claim that most people believe that the Loch Ness monster exists.
B.
Fail to reject
H0.
There
is not
sufficient evidence to warrant rejection of the claim that most people believe that the Loch Ness monster exists.
C.
Reject
H0.
There
is
sufficient evidence to support the claim that most people believe that the Loch Ness monster exists.
D.
Fail to reject
H0.
There
is
sufficient evidence to warrant rejection of the claim that most people believe that the Loch Ness monster exists.
How is the conclusion affected by the fact that Internet users who saw the question could decide whether to respond?
A.
Since only certain users are being allowed to respond, the conclusion is not valid.
B.
Since the sample size is sufficiently large, the conclusion is valid.
C.
Since any of the site's users are allowed to respond, the conclusion is valid.
D.
Since the sample is a voluntary-response sample, the conclusion might not be valid.