Answer:

Explanation:
Give that for every 1000 feet increase in the height there is a drop of
in temperature.
So, the rate of temperature drop with respect to height, R = 1.7/1000
.
If the change in height is

feet, the temperature drop,

The temperature on the ground is 49.9
.
At the ground, the height is 0, so the change in height, \Delta h when the plane reaches an altitude of 4,000 feet, is
\Delta h =4000-0=4000 feet
Now, from equation (i), the temperature drop

Hence, the temperature at an altitude of 4000 feet
.