My understanding is that Raghu has a sensor the gives him a reading value that corresponds to the second column of his table. From this he wants to interpolate the degrees. My understanding is that the sensor is attached to his microcontroller and that it gets the readings and needs to infer the degrees from the readings.

If I was taking on this problem I would exapand the 2nd column by turning the table inside out so that the an upper portion of the sensor reading can be a direct index into the lookup table. This eliminates a search to find the entries in the table wherein the interpolation needs to be done. That said however it may be that a simple linear scan is just plain good enough becasue there are so few entries in the table.

Michael Karas