In the linked article, towards the middle, the photo shows 2 people reading the plaque next to a pink structure, which appears to be that of a whale's heart. That, combined with the skeleton hanging over them, should give us an idea that we are no bigger to these whales, than probably an average snail is to us (between 5 cm and 9 cm).
But let me just add up their lengths, along with the lengths of all giant african land snails and all other snails, and divide by the total number of snails in the world ... is there a statistical trick that could answer this, like the one for counting undiscovered species? Probably not.
In the linked article, towards the middle, the photo shows 2 people reading the plaque next to a pink structure, which appears to be that of a whale's heart. That, combined with the skeleton hanging over them, should give us an idea that we are no bigger to these whales, than probably an average snail is to us (between 5 cm and 9 cm).