help, have no math skills! meteorology question / relative humidity

Please be nice, I have no idea if I'm on the proper website for this kind of help.

I don't know what my math problem would be classified as, so I'm just guessing that it fits here.

Nevertheless, I really need help with this problem. It's worth badly needed extra credit for a class of mine.

Relative humidity = [(vapor pressure) / saturation vapor pressure)] x 100

The question is: **What is the vapor pressure when relative humidity is 67 %, and the temp is 80.6 F? **

At 77 F the saturation vapor pressure is 31.67. At 86 F it's 42.43.

Anyone?