PERT: +/-2 sigma (Probability 95.46%)

Good Day All:

How do I take the following excel formula and use it smartsheet to get the same results 

Excel formula =$G$30-2*SQRT($I$30)

Results: 1.33

Smartsheet Formula =$Expected$26-2*SQRT($Variance$26)

Results: UNPARSEABLE

I tried using ^2 for square root but still receive the same results.

Thanks