In March, 2019, Gallup published an online article by Frank Newport titled, “American’s Views of Israel Remain Tied to Religious Beliefs.” For the article Mr. Newport reviewed data previously collected by Gallup in several national random samples and focused on the responses from 128 Jewish Americans. Of these respondents, 110 indicated that they were sympathetic toward Israel. a) Use the four-step process to construct and interpret a 95% confidence interval for the proportion Jewish Americans who are sympathetic toward Israel.

b) Find the 99% confidence interval (no need to interpret).

c) Find the 90% confidence interval (no need to interpret).

d) Rewrite all three confidence intervals from the previous page.

90% confidence interval:
95% confidence interval:
99% confidence interval:
As the confidence level went up, what happened to the confidence interval?

What can you say about how precision (width of the confidence interval) and confidence level are related?

How can we have both a narrow interval and a high level of confidence? Note: you may not be able to answer this question yet. But we’ll do a little exploration in the next module that may be able to help.