Question

In the early 1990s, there were approximately 5 billion people in the world. Plous† asked readers to estimate how wide a cube-shaped tank would have to be to hold all of the human blood in the world. The correct answer is about 870 feet, but most people give much higher answers. Explain which of the concepts covered in this chapter leads people to give higher answers. (Hint: Compare 870 to 870³.) (Select the correct answer)

People use the fact that there are 5 billion people in the world as an anchor. They picture a very large container and do not adjust for the fact that a cube has the width multiplied by itself three times.

The most available metric people call to mind for estimating volume tends to be structures like skyscrapers or football fields, and they are unsure of how to convert them to cubic meters.    

People get caught up in the estimation of the number of gallons of blood in the human body and converting this to cubic feet that they forget the base rate of the number of people in the world.

Most people are overconfident in their abilities at mathematics, so they would be unable to calculate the volume of such a container.

Answer 1