Looking up values on another chart

Hello,
I've got kind of a two-part question. I'm building a spreadsheet for liquid volume corrections based on pressure and temperature. I've got another chart on the same sheet listing set values for a certain correction factor based on temperature. Once I enter the temperature, is there any way to have it automatically look up the correction factor from the chart below?
Secondly, the aforementioned chart only lists integer values for temperature. Can I get it to extrapolate for decimal values? For example, if the temperature entered is 86.8, I want the correction factor for 86 plus 80% of the difference between the values for 86 and 87.

Thanks!