A standard altimeter indicates 20,000 ft when the ambient temperature is 40 ℉. Calculate the density in slug / ft^3. (*I

[answerhappygod]

A standard altimeter indicates 20,000 ft when the ambient
temperature is 40 ℉. Calculate the density in slug / ft^3.
(*Incorporate both the altimeter value and temperature in the
computation.)
Constants:
Po = 2116.8 lbs / ft^2
a = -0.003566 °R / ft
To = 519 °R
R = Universal gas constant = 53.342 ft / °R
g = gravity (32. 174 ft/ s^2)
ρo = 0.002377 slug / ft^3