Question

Which of the following calculations is NOT derived from the confidence interval?

Choose the correct answer below.

  

A.

Difference between the limits,

2E=(upper confidence limit)−(lower confidence limit)

B.

The population mean,

μ=(upper confidence limit)+(lower confidence limit)

C.

The margin of error,

E=(upper confidence limit)−(lower confidence limit)2

D.

The point estimate of µ,

x=(upper confidence limit)+(lower confidence limit)2

Answer 1

The answer is B.

 This is a symmetric CI, hence sample mean (which is the point estimate of the population mean) is x̅ = (upper + lower)/2

 Margin of error = 1/2 x Length of CI = (upper-lower)/2

 Since the population means may not be equal to the sample mean, the population mean may not be equal to the sample mean, which is at the center of the two boundaries.