You are watching a nightly news broadcast on CNN and the
reporter says that a 99% confidence interval for the proportion of
Americans who supported going to war in Iraq was ( 0.2374 , 0.3139
). You also note that the footnote says this is based on a random
sample performed by Gallup with 907 respondents. What is the
correct interpretation of this confidence interval?
Question 8 options:

1)

We are certain that 99% of Americans will be between 0.2374 and
0.3139. 


2)

We are 99% confident that the proportion of all Americans
surveyed who supported going to war in Iraq is between 0.2374 and
0.3139. 


3)

We are 99% confident that the proportion of all Americans who
supported going to war in Iraq is between 0.2374 and 0.3139. 


4)

We are 99% confident that of the 907 respondents, between
0.2374 and 0.3139 of them supported the decision to go to war. 


5)

We cannot determine the proper interpretation of this
interval. 

Question 9 (1 point)
Political party affiliation is believed to be a very strong
indicator of how voters will vote in Presidential Elections. You
are interested in determining if voter party loyalty has changed
since 1992. During the 1992 election, the proportion of
selfproclaimed Republicans who voted for George H. W. Bush was
0.816. During the 2012 election, in a survey of 310 Republican
voters, 236 indicated that they had voted for Mitt Romney. The 90%
confidence interval for this proportion is ( 0.7215 , 0.8011 ).
What is the best conclusion you can make from this information that
is listed below?
Question 9 options:

1)

The confidence interval does not provide enough information to
form a conclusion. 


2)

We can conclude that the proportion of selfproclaimed
Republicans who voted in the 2012 election for their party
candidate is larger than 0.816. 


3)

The proportion of selfproclaimed Republicans who voted for
their party candidate in 2012 who changed from 0.816 is 90%. 


4)

We can not conclude that the proportion of selfproclaimed
Republicans who voted in the 2012 election for their party
candidate differs from 0.816. 


5)

We can claim that the proportion of selfproclaimed Republicans
who voted in the 2012 election for their party candidate is smaller
than 0.816. 
