z-score of length X is (X-m)/s where m=mean and s=SD. We need X so that P(z)=0.07 and 0.93.
z=-1.475 is the value of z for the lower 7% and so 1.475 is the value for the upper 7%.
(X-4.63)/0.06=-1.475 gives 0.0885=4.63-X, X=4.54cm. (X-4.63)=0.0885, X=4.72cm. So the difference is 0.18cm.