forget about lowest/highest.
you want a y = a + bx where x is input v and y is output pressure.
Find a and b such that y is correct for two x inputs. Pick two. Any two. Find a and b.
Thanks for your effort Nyet.
Result the same thing like what result from FR formula. All depends the input values. I remaining with 500hpa and 0.5V and 4000hpa and 4.5v , will be 875 and 62.5. I devided with 2 both of them and result like JDM said. I have 2 specification for this map sensor and they show 2 different values for 4000hpa. One had 4.5v other had 4.65v for the same 400hpa.
Today i tried 437.5 and 31.25 ( i made this thing 2-3 month ago and doesn't work , maybe something was wrong in the file), for some 30km and 3-4 WOT logs works ok with some idle fluctuation but my file is not adjusted, all cells of fkkvs , kflf and kfkhfm are 1.