Chauncey determined that 50 percent of students at his school voted Republican in the last election,with a sampling error (also known as standard error)of 5 percent.What is the confidence interval for 95 percent confidence level?
A)35 to 45 percent
B)35 to 55 percent
C)40 to 55 percent
D)40 to 60 percent
E)35 to 60 percent

Question

Quizplus · Accepted Answer

The confidence interval is calculated as the sample proportion plus and minus the margin of error. For a 95% confidence level, the margin of error is approximately 1.96 times the standard error. Here, 50% ± (1.96 * 5%) gives a range of 40% to 60%.

Chauncey Determined That 50 Percent of Students at His School