Final answer:
The average speed of the plane was approximately 352 mph, calculated by dividing 2006.4 miles by 5.7 hours. The answer closest to this calculation in the options given is A) 351.16 mph, indicating a possible calculation error or rounding difference in the options provided.
Step-by-step explanation:
To calculate the average speed of the plane, we can use the formula:
average speed = total distance traveled / total time
In this case, the plane flew 2006.4 miles in 5.7 hours.
Now, we just divide the distance by the time to find the average speed:
2006.4 miles / 5.7 hours = 352 mph
Therefore, the average speed of the plane was approximately 352 miles per hour, which is none of the options provided A) 351.16 mph B) 391.07 mph C) 430.24 mph D) 472.27 mph. There appears to be a discrepancy between the calculated figure and the options listed; the correct answer is closest to option A) 351.16 mph, so there might be a slight calculation error or rounding difference in the question.