I need to extrapolate the following graph.

Could someone help me with the formula for the logarithmic graph?

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- read two points from the graph, for example
`(1,200)`

and`(1000,10)`

(those are the points at the right and left border). - Calculate the log10 for each:
`(0,2.301)`

,`(3,1)`

. - Use those two points to fit a line through -
`y = ax+b`

=>`2.301 = 0a +b`

;`1 = 3a +b`

=> the first one conveniently collapses to`b=2.301`

, and using this in the second one gives`a=-1.301/3=-0.434`

So your line is `y = -0.434 x + 2.301`

, and if you want it back in the base variables `log(p) = -0.434*log(t) + 2.301`

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