Question

After this year's Iowa caucuses, a random sample of 80 voters were asked if they support changing the ordering in which states hold their presidential primary contests. Based on this sample, a 95% confidence interval for theproportion of voters who are in favor of changing the ordering was (0.54, 0.72).

1) Which of the following is true?

A. 95% of the sampled voters are in favor of changing the ordering.

B. the margin of error for the confidence interval is 0.18

C. a larger sample size would yield a wider confidence interval

D. The method used to construct the interval done so as to contain p 95% of the time

E. none of the above are true

2) Let p be the true proportion of voters who are in favor of changing the ordering in which states hold presidential primary contests. Based on the reported 95% confidence interval, which of the following statements is most appropriate?

A. The point estimate p̂ is 95% accurate for p

B. 95% of the time, the true proportion of voters who are in favor of changing the ordering in which states hold presidential primary contests is between (0.54, 0.72).

C. There is a 95% chance that the true proportion is in the interval (0.54, 0.72).

D. If we were to repeat this study 100 times, approximately 95 of intervals constructed using this method would contain p

E. The sample proportion has a 95% chance of falling between the endpoints (0.54, 0.72).

Answer 1

1) 95% confidence interval for the proportion of voters who are in favor of changing the ordering is (0.54, 0.72).

D) The method used to construct the interval done so as to contain p 95% of the time

2)

B) 95% of the time, the true proportion of voters who are in favor of changing the ordering in which states hold presidential primary contests is between (0.54, 0.72).