Final answer:
The length of a city block running north to south in New York City is approximately 10.3 blocks.
Step-by-step explanation:
The length of a city block running north to south in New York City is approximately 10.3 blocks. To find the length, we can use the Pythagorean theorem as the distance walked in the east direction (9 blocks) and the distance walked in the north direction (5 blocks) form a right triangle. The hypotenuse of this triangle represents the straight-line distance which is the length of the city block.