Can I have the excel function and inputs to get 71.57%?

Probability of Completion Project variance =( Variances of activities on critical path ) Projectvariance(p2)=0.11+0.11+1.00+1.78+0.11=3.11 =3.11 Project standard deviation (p)=Projectvariance =3.11=1.76 Z=( Target completion time Expected completion time )/p =(16 weeks 15 weeks )/1.76 weeks =0.57 probability of completing the project in 16 weeks or less =71.57%