You choose a simple random sample of 2000 women over 18 years of age from the New York City metropolitan area; 623 of them are single. A 90% confidence interval for the proportion of all adult women in the New York area who are single is (approximately)
A) 0.3115 ± 0.017.
B) 0.623 ± 0.017.
C) 0.3115 ± 0.0207.
D) 0.623 ± 0.0207.
E) 0.3115 ± 0.0267.

Question

Quizplus · Accepted Answer

The proportion of single women in the sample is 623/2000 = 0.3115. A 90% confidence interval typically involves a smaller margin of error compared to a 95% confidence interval, making option A (0.3115 ± 0.017) a plausible choice for a 90% confidence interval around the sample proportion.

You Choose a Simple Random Sample of 2000 Women Over