Question

Greg Salzman is flying from Chicago. The pilot announced that the plane was flying at an altitude of 28 comma 000 feet. The man seated next to Greg asked him to estimate how many miles high the plane was at that point. How should Greg answer the​ man? (Hint: First round the altitude to the nearest ten thousand feet. Then round the conversion equivalent for the number of feet in a mile to the nearest thousand feet. Then perform the​ calculation.)

Answer 1

To estimate how many miles high the plane was flying at an altitude of 28,000 feet, Greg should follow these steps:

1. Round the altitude to the nearest ten thousand feet:
   The altitude is 28,000 feet, which is already at a ten thousand mark, so it stays as 28,000 feet.

2. Round the conversion equivalent for the number of feet in a mile to the nearest thousand feet:
   There are 5,280 feet in a mile. Rounding this to the nearest thousand gives us 5,000 feet.

3. Perform the calculation:
   To find the altitude in miles, divide the altitude in feet by the rounded conversion factor (5,000 feet per mile): \[ \text{Miles} = \frac{28,000 \text{ feet}}{5,000 \text{ feet/mile}} = 5.6 \text{ miles} \]

Therefore, Greg should answer that the plane was approximately 5.6 miles high.