For the answer to the question above, I'll provide a computation on my answer to give clarity and understanding to my answer.
P(z> 0.64) = 1- P(z<0.64)
P(z<0.64) = .73891
P(z> 0.64) = 1- 0.73891 =
So the answer to your question is
0.26109
I hope my answer helped you. Have a nice day!