Answer:
The plane can go 2.8 miles higher without leaving troposphere.
Explanation:
Troposphere extends from the earth's surface to a height of 6 - 12 miles which varies on different locations.
If a plane is flying at an altitude of 5.8 miles.
The altitude of the troposphere is 8.6 miles deep from that location.
Therefore, the plane can go more up without leaving the troposphere = 8.6 - 5.8 = 2.8 miles