Which of the following assumptions must be true in order to use the formula $$\bar { X } \pm z _ { a/2 } ( \sigma / \sqrt { n } )$$ to find a confidence interval estimate of the population mean?
A)The population variance is known.
B)The population mean is known.
C)The population is normally distributed.
D)The confidence level is greater than 90%.

Question

Quizplus · Accepted Answer

The Answer of Which of the following assumptions must be true in order to use the formula $$\bar { X } \pm z _ { a/2 } ( \sigma / \sqrt { n } )$$ to find a confidence interval estimate of the population mean?
A)The population variance is known.
B)The population mean is known.
C)The population is normally distributed.
D)The confidence level is greater than 90%.

Which of the Following Assumptions Must Be True in Order Xˉ±za/2(σ/n)\bar { X } \pm z _ { a/2 } ( \sigma / \sqrt { n } )Xˉ±za/2​(σ/n​)

Which of the Following Assumptions Must Be True in Order $\bar { X } \pm z _ { a/2 } ( \sigma / \sqrt { n } )$