To convert the speed of the airplane from kilometers per hour to miles per hour, you can use the conversion ratio of 1 kilometer equals 0.62 miles.
Given that the airplane travels at 900 kilometers per hour, you can calculate the speed in miles per hour as follows:
\[ \text{Speed in miles per hour} = \text{Speed in kilometers per hour} \times 0.62 \] \[ \text{Speed in miles per hour} = 900 \times 0.62 = 558 \]
Therefore, the airplane’s speed in miles per hour is 558.