Statistical Significance of data Based on Criteria

I am trying to duplicate the calculations that are done on the following site: www.splittester.com, through the use of an excel function.

The purpose is to calculate the statistical significance of data. I have inserted comments to show which rows I wish to calculate, and which is the criteria data.

Hi there. I'm a researcher and know something about statistics, but I can't tell from the website what the exact statistical test used is. Perhaps a chi-squared test? I would have thought a Student's T-test, or something similar.

Anyway you can't generate results about statistical significance from the STDEV function: that's just a measurement of variance. To get to comparing the variances between two values or ranges, then you have to use other functions (e.g. TTEST). Interpreting your results is then another step.