Answer:
24 degrees Fahrenheit.
Step-by-step explanation:
The moist adiabatic rate is related to the variation of the temperature as the altitude increases.
A typical value is around 9ºF/km. This means that for each km, the temperature decreases 9ºF.
In this problem, we have that:
The temperature at the ground level is 60 degrees Fahrenheit.
So 4km above sea level it is going to be 60 - 4*9 = 24 degrees Fahrenheit.