The correct option is A 8.2x103
It is given that, the length of the typical airline runway is 8200 ft.
4.1 ×102 = 4.1 × 100 = 410 ft
8.2 ×102 = 8.2 × 100 = 820 ft
82.2 ×102 = 82.2 × 100 = 8220 ft
8.2 ×103 = 8.2 × 1000 = 8200 ft
Hence, the length of the runway in scientific notation is 8.2 ×103 ft