An alternative:
Profili software is very inexpensive and requires no particular skills to use. If you tell it the root and tip chords and how many ribs you want, you can select a wing section from its library or make your own. It will generate all the ribs in between. You can use differently shaped sections for root and tip, and it will interpolate, giving you the progressively-changing ribs between. It can also be made to create recesses and cut-outs for spars, lead-outs, lightening holes, etc. It does elliptical wings too. Once you have this tool, you will always be able to do this simply. When building from plans, you'll often find that the designer has used an NACA section from the library.
It's worth the effort to get it and just use it when needed.
SK