Can taller peoples lungs hold more air? - 3rd and 4th class

Question

Can taller peoples lungs hold more air than shorter peoples lungs?

Prediction (Hypotheses)

Each class member formed their own (justified) hypothesis. By and large the class thought that taller people's lungs would hold more air.

 Test

We considered the tallest and shortest people in the class blowing air into a plastic bag, and inspecting. However, we dismissed this as we could not measure it very well and it was only 2 people.
We used a test involving displacing water in a full bottle and measuring how many millilitres was displaced.
The entire class did this in teams of three, both as scientist and subject,  and everyone's height was measured.

The data was recorded in Excel, see technology blog, and we discussed how a scatter graph would look if taller peoples lungs could/couldn't hold more air, see maths blog.

Results

Our class results were inconclusive, so we took further data during our school science fair.