Choose the one alternative that best completes the statement or answers the question.
-The cell phone conversations of a random sample of 50 students has a standard deviation of 9.7 minutes. Find the margin of error, E, using a 90% confidence interval.
A) 2.26
B) 0.32
C) 1.37
D) 1.23

Question

Quizplus · Accepted Answer

The margin of error is E = z * (s/√n), where z is the z-score corresponding to the desired confidence level, s is the sample standard deviation, and n is the sample size. For a 90% confidence level, z = 1.645. Plugging in the given values, we get E = 1.645 * (9.7/√50) = 2.26.

Choose the One Alternative That Best Completes the Statement or Answers