Answer:
Nathan's estimate would be greater than the actual product.
Step-by-step explanation:
Let a, b, c, d be natural numbers such that a<c and b<d
Multiplying a positive number on both sides doesn't affect the inequality
⇒a×b < c×b and c×b < c×d
⇒a×b < c×d
Here 67<70 and 36<40
∴67×36<70×40
Hence, Nathan's estimate would be greater than the actual product.