The population here refers to the all the wild elephants that are present in that particular geography. This refers to the whole universe of wild elephants present in the area,
The sample is the 400 elephants that the biologist tranquilized to mesaure the length of their tusks.
So, to conclude, population = all wild elephants present and sample = 400 elephants that were tranquilized
sibusiso= 4 chocolates
dorris= 6 choclates
freddy= 10 chocolates