Here's why you shouldn't jump to conclusions about the cadence-power relationship. These data were collected during a ride with a series of hill intervals. Here's a plot showing the data collected on the flat (in black) and the data collected on the hill (in red).
And, just to make clearer the relationship between cadence and power during those two parts of the ride, I've superimposed two smooth lines that show the average power at each cadence level, a red line to show the power on the hill and a black line to show the power on the flat. The relationships are opposite.
Are you now willing to say what the relationship between cadence and power is?