In a random sample of n = 400 people, 40% say they have allergies. The conservative margin of error is reported to be 5%. What is a 95% confidence interval for the percent of the population that has allergies?
A) 25% to 55%
B) 30% to 50%
C) 35% to 45%
D) 40% to 45%

Question

Quizplus · Accepted Answer

The sample proportion is 40%, and the margin of error is 5%. Therefore, the confidence interval is 40% ± 5%, which is 35% to 45%.

In a Random Sample of N = 400 People, 40