how to calculate the speed of sound at temp of -83F and 135F?
The speed of sound is proportional to the square root of the absolute temperature, T, and the formula is
V = sqrt(gamma*R*T)
where gamma is the specific heat ratio (1.4 for air) and R is the gas law constant.
If you are not very far from "room temperature", it is much easier to use the linearized formula than can be found at
http://www.iu.edu/~emusic/acoustics/speed.htm