We are trying to find the average speed of the plane, which is mph, or . Using proportions, we can find the average speed of the plane in mph:
- Use the information from the problem to create a proportion. Remember that we are looking for mph, so we will call that
.
- Multiply the entire equation by
- Divide both sides of the equation by
to clear both sides of the mile unit
The average speed of the plane is 300 mph.