We extract one portion of the table and add our required unknown, as follows:

Temp 30 36 40
Rate 0.30 ?? 0.37

Using proportions again, we have:

`b = y_1 + (y_2 - y_1)(a - x_1)/(x_2 - x_1)`

` = 0.30 + (0.37-0.30)(36-30)/(40-30)`

`= 0.30 + (0.07)(6/10)`

` = 0.30 + 0.042`

` = 0.342\ "mg/min"`

So the required value is:

Rate `= 0.342\ "mg/min"`.

Easy to understand math videos:
MathTutorDVD.com