IF 3 variables then return a specific #

I've attached the example spreadsheet.
I have 3 columns with multiple variable rows.
The 4th column is the specific result for those 3 variables.
I need a formula/s that will give me the correct 4th column # based on the previous 3 columns what would be input using dropdown lists I believe.

So for instance the final end result would be an HTML web page with 3 drop down boxes representing the first 3 columns and then based on what is selected in those 3 dropdowns the correct 4th column # would be shown.

Any help would be greatly appreciated by this great community.