Question

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 self-proclaimed 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 self-proclaimed Republicans who voted in the 2012 election for their party candidate is larger than 0.816.

3)	The proportion of self-proclaimed 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 self-proclaimed Republicans who voted in the 2012 election for their party candidate differs from 0.816.

5)	We can claim that the proportion of self-proclaimed Republicans who voted in the 2012 election for their party candidate is smaller than 0.816.

Answer 1