Question

If X =65, standard deviation = 7 and n = 63 construct a 99% confidence interval estimate for the population mean.

Also, would anyone know how to do this in Excel?

Answer 1

Using Excel,

Here population standard deviation is not given so we use t .

Press Ok

A 99% confidence interval estimate for the population mean is,

(62.656 , 67.344)

(62.66 , 67.34) ................(Rounded to 2 decimal )

Using Z

One sample Z summary confidence interval:

μ : Mean of population
Standard deviation = 7

99% confidence interval results:

Mean	n	Sample Mean	Std. Err.	L. Limit	U. Limit
μ	63	65	0.8819171	62.728332	67.271668

(62.73 , 67.27)