Two monochromatic light beams, Beam 1 and Beam 2, travel through a vacuum and enter a flat block of dispersive glass of thickness \(L\) at normal incidence. In a vacuum, Beam 1 has wavelength \(\lambda_1\) and Beam 2 has wavelength \(\lambda_2 = 1.5\lambda_1\). Due to chromatic dispersion in the glass, the index of refraction for Beam 1 is \(n_1\), whereas the index of refraction for Beam 2 is \(n_2 = 0.80n_1\). What is the ratio \(\dfrac{N_1}{N_2}\) of the number of wavelengths of Beam 1 contained within the glass block to the number of wavelengths of Beam 2 contained within the glass block?