CONFIDENCE.NORM
Category: Statistical Function.
Description: Returns the confidence interval for a population mean, using a normal distribution.
Syntax: CONFIDENCE.NORM(alpha,standard_dev,size)
'Alpha' is the significance level used to compute the confidence level.
The confidence level equals 100*(1 - alpha)%, or in other words, an alpha of 0.05 indicates a 95 percent confidence level.
'Standard_dev' is the population standard deviation for the data range and is assumed to be known.
'Size' is the sample size.