The employees of Cybertronics Inc.need to complete a certification online.A random sample of 49 employees gives an average time for completion of all the coursework and passing the tests of 20 hours.Assume that the population standard deviation is 6 hours and the population of employees is fairly large.Construct a 95% confidence interval for the average time required to complete the certification.
A)18.28 to 21.72
B)18.32 to 21.68
C)18.36 to 21.64
D)18.40 to 21.60
E)19.76 to 20.24

Question

Quizplus · Accepted Answer

The 95% confidence interval is calculated using the formula: mean ± Z*(σ/√n). Here, the mean is 20, Z is 1.96 for 95% confidence, σ is 6, and n is 49. This results in the interval 18.32 to 21.68.

The Employees of Cybertronics Inc