Answer:
San Francisco with average speed of 639 km/hour
Step-by-step explanation:
Phoenix 3 1,689
Minot 2 913
San Francisco 4 2,556
Phoenix average speed = distance travelled / time taken
= 1,689 km /3 hours
= 563 km/hour
Minot average speed = distance travelled / time taken
= 913 km / 2 hours
= 456.5 km/hour
San Francisco average speed = distance travelled / time taken
= 2,556 km / 4 hours
= 639 km/hour
The fastest average speed flight is San Francisco with an average speed of 639 km/hour
