In survey conducted by Quinnipiac University from October 25-31, 2011, 47% of a sample of 2,294 registered voters approved of the job Barack Obama was doing as president.What is the 99% confidence interval for the proportion of all registered voters who approved of the job Barack Obama was doing as president?A) (0.460, 0.480)B) (0.453, 0.487)C) (0.450, 0.490)D) (0.443, 0.497)

Answer:Confidence interval = [ 0.4432, 0.4968]Step-by-step explanation:Registered voters approved of the job Barack Obama was doing as president,p = 47% = 0.47Total sample size, n = 2,294Confidence level = 99%now,confidence interval for the proportion of all registered voters who approved of the job Barack Obama was doing as president= p ± [tex]z\times\sqrt{\frac{p\times(1-p)}{n}}[/tex]for 99% confidence level, z value is 2.58 = 0.47 ± [tex]2.58\times\sqrt{\frac{0.47\times(1-0.47)}{2294}}[/tex]= 0.47 ± 0.0268 orConfidence interval = [0.47 - 0.0268, 0.47 + 0.0268 ]orConfidence interval = [ 0.4432, 0.4968]