You plan to construct a confidence interval for the mean μ of a Normal population with (known) standard deviation σ. Which of the following actions will reduce the size of the margin of error?

Question

Quizplus · Accepted Answer

The margin of error in a confidence interval for the mean μ of a Normal population with known standard deviation σ can be reduced by using a lower level of confidence (which decreases the critical value), increasing the sample size (which increases the denominator in the margin of error formula), or reducing σ (which directly reduces the standard error).

You Plan to Construct a Confidence Interval for the Mean