Question 1179342
one can use invnorm(.03,13.9,3.7) and the answer is 6.94 years or 6.9 years.
z=(x-mean)/sd
z(0.03)=-1.88
so -1.88=(x-13.9)/3.7
and x-13.9=-6.96
x=6.94 years or 6.9 years