211 Final Exam Questions With Complete Solutions

What happens to the confidence interval as the confidence level increases? {Ans: The confidence interval gets wider (L. limit decreases and U. limit increases).}A polling company conducts an annual poll of adults about political opinions. The survey asked a random sample of 328 adults whether they think things in the country are going in the right direction or in the wrong direction. 44​% said that things were going in the wrong direction. A. No, because the sample is a simple random​ sample, the sample proportion is between​ 10% and​ 90%, and there are at least 20 expected​ "successes" and 20 expected​ "failures." B. Yes, because the sample is a simple random​ sample, the sample is less than​ 10% of the​ population, and there are at least 10 expected​ "successes" and 10 expected​ "failures." C. ​No, because the sample is a simple random​ sample, the sample is less than​ 10% of the​ population, and there are at least 10 expected​ "successes" and 10 expected​ "failures." D. Yes, because the sample is a simple random​ sample, the sample proportion is between​ 10% and​ 90%, and there are at least 20 expected​ "successes" and 20 expected​ "failures." {Ans: B. Yes, because