Photon frequency scales with photon energy; this book uses exact ratios instead of absolute constants. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Photon energy and frequency scale together
In this ratio-only lesson, doubling photon energy means doubling frequency. Absolute constants are deferred.
E∝f
A doubled energy ratio gives doubled frequency
If one photon energy is 3/4 and another is twice as large, the frequency ratio is 2.
fbaseflarger=2
Energy ratios and frequency ratios match
Because the lesson is ratio-only, the frequency column repeats the energy ratio column. This is the only numeric claim.