The student newspaper at a college asks a simple random sample of 250 undergraduates, "Do you favor eliminating supplemental fees for lab courses?" In all, 150 of the 250 are in favor of eliminating such fees.
A 90% confidence interval based on this same sample would have
A) the same center and a larger margin of error.
B) the same center and a smaller margin of error.
C) a larger margin of error and probably a different center.
D) a smaller margin of error and probably a different center.
E) the same center, but the margin of error changes randomly.

Question

Quizplus · Accepted Answer

A 90% confidence interval would have the same center (sample proportion) but a smaller margin of error compared to a 95% confidence interval, as a lower confidence level results in a narrower interval.

The Student Newspaper at a College Asks a Simple Random