\(f=\tau_0=\frac{R_n^2}{n \lambda}\)

\(D_n=2R_n=2\sqrt{n \lambda \tau_0}\)

the first two maxima:

\(D_1=2\sqrt{(1)(5.893*10^{-5}cm)(150cm)}=0.188cm\)

\(D_3=2\sqrt{(3)(5.893*10^{-5}cm)(150cm)}=0.326cm\)

the first two minima:

\(D_2=2\sqrt{(2)(5.893*10^{-5}cm)(150cm)}=0.266cm\)

\(D_4=2\sqrt{(4)(5.893*10^{-5}cm)(150cm)}=0.376cm\)