Oddly, the best hope for avoiding that 90-day wait could come from your cable company. HBO says it's in discussions with some cable, satellite and telephone providers that could sell access to HBO Now at launch, but nothing is set so far.
1 Use the Excel Formula =STDEV() and select the range of values which contain the data. 2  This calculates the sample standard deviation (n-1).3  Use the web Standard Deviation calculator and paste your data, one per line. Use the Excel Formula =STDEV() and select the range of values which contain the data. 2  This calculates the sample standard deviation (n-1).
Confidence Function Example. In the spreadsheet below, the Excel Confidence Function is used to calculate the confidence interval with a significance of 0.05 (ie. a confidence level of 95%), for the mean of a sample of heights of 100 men.The sample mean is 1.8 meters and the standard deviation is 0.07 meters.he Excel CONFIDENCE function uses a Normal Distribution to calculate a confidence value that can be used to construct the Confidence Interval for a population mean, for a supplied probablity and sample size.