I am trying to develop a spreadsheet where the user chooses a 'Fuel' from a drop down box, inputs some other parameters and the spreadsheet returns a value, as well as a graph (on which the output value lies).

For each fuel there are four variables that need to be entered into a formula: A B C and R. So my first question is how do I 'group' these variables with the fuels so that they can be substituted into a formula upon selection of a fuel from a drop down menu?

To make things more complicated some of the fuels have different values of A B & C according to different temperature ranges, furthermore the required output is the Temperature.. so is it possible therefore to use an IF function should the result not fall in the correct temperature range and perform another iteration (using different A B C values) to find the correct temperature?

Here is a screenshot of the Fuel table as it stands:

image.jpg

The variables to be entered in to a formula are in columns J N O & P. Columns L&M show the temperature ranges for the A B C variables. I hope I'm sense sense here and your following me.

To the left of the table (out of sight) is another small table with a few constants that are used in the formula. (I will probably move this to another sheet to tidy things up a bit).

On a seperate sheet I need another table where the user types some other variables, one of which limited to within a certain range, and on the right a graph which changes for the fuel selected.

I hope somebody can help me!

Im using Excel for Mac 2011

Cheers
Gaz