Question

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 0.893. During the 2012 election, in a survey of 264 Republican voters, 198 indicated that they had voted for Mitt Romney. The 99% confidence interval for this proportion is ( 0.6814 , 0.8186 ). What is the best conclusion you can make from this information that is listed below?

Question 6 options:

1)	We can not conclude that the proportion of self-proclaimed Republicans who voted in the 2012 election for their party candidate differs from 0.893.

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

3)	The proportion of self-proclaimed Republicans who voted for their party candidate in 2012 who changed from 0.893 is 99%.

4)	We can conclude that the proportion of self-proclaimed Republicans who voted in the 2012 election for their party candidate is larger than 0.893.

5)	We can conclude that the proportion of self-proclaimed Republicans who voted in the 2012 election for their party candidate is smaller than 0.893.

Answer 1

The 99% confidence interval for this proportion is ( 0.6814 , 0.8186 ).

The proportion of self-proclaimed Republicans who voted for George H. W. Bush was 0.893.

The null and alternative hypothesis is

H0: P = 0.893

H1: P 0.893

The value 0.893 is not in the above confidence interval so we reject the null hypothesis.

Conclusion:

5) We can conclude that the proportion of self-proclaimed Republicans who voted in the 2012 election for their party candidate is smaller than 0.893.