Stat function does not work

I purchased the calculator in hopes that it would work for a class presentation that I was recording. I wanted to work through problems with students using it. The first problem I did was to calculate the standard deviation using the Data and Stat function. While it properly calculated the mean, it did not calcuate the standard deviation. Very disappointing for a $15 app. Wish I could get my money back.

Wash man about BA Pro Financial Calculator