y/x = k
6.4/4 = 1.6
11.2 / 7 =1.6
16/10 = 1.6
20.8 /13 =1.6
This is a direct variation and the constant is 1.6
y=1.6x
Answer
I would say Chimpanzees
Step-by-step
Not only are they our closest ancestors, they are one of the few animals that actually use tools to get food. They're pretty interesting creatures
