how to determine confidence interval in excel
The first step is gather the data you want to base the confidence calculation into an excel spread sheet. Put them all in a column and use the COUNT function to determine the number of data points you want to base you calculation on.In this case, there are 20 data points and the value of the count calculation is 20. Calculate the standard deviation of the data.The standard deviation is used to measure the variability of a data set and it is a key value of the confidence calculation. In Excel, this is done with the STDEV function.he first step is gather the data you want to base the confidence calculation into an excel spread sheet. Put them all in a column and use the COUNT function to determine the number of data points you want to base you calculation on.