Rather than having to remember the formulas (and remembering how to use them), I came up with a way that is much easier, for me anyway:

This example is set at tempo = 160
Create a measure with 8 eighth rests in it.
Insert tempo marks before each eighth rest.
Before 1st, 3rd, 5th, & 7th eighth rests, set tempo to dotted-eighth = 160.
Before 2nd, 4th, 6th, & 8th eighth rests, set tempo to dotted-quarter = 160.
(I usually use Copy&Paste to do this more quickly.)
Then you can use either the local repeat feature or you can Copy&Paste as many measures as you need, in case you need one straight measure somewhere in there. For that measure, simply enter quarter-note = 160 at the beginning of the measure with no other tempo marks anywhere else in that measure.