The formula f = 5280m can be used to convert a measurement of f feet to an equivalent measurement of m miles. If an airplane flies at 21,120 feet above the ground, how much is that in miles?

Question 3 options:

4 miles

111,513,600 miles

5.3 miles

132,620,600 miles

To convert feet to miles using the given formula, you need to divide the measurement in feet by the conversion factor, which is 5280.

21,120 feet รท 5280 = 4 miles

Therefore, the airplane flying at 21,120 feet above the ground is equivalent to 4 miles.