Bulk pressure change follows modulus times volume-change ratio. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Bulk pressure follows modulus times volume-change ratio
Volume change 1 cubic meter over volume 6 cubic meters with modulus 12 Pa gives pressure change 2 Pa.
ΔP=KVΔV=12Pa⋅6m31m3=2Pa
Bulk pressure follows modulus times volume-change ratio
Volume change 2 cubic meters over volume 12 cubic meters with modulus 12 Pa gives pressure change 2 Pa.
ΔP=KVΔV=12Pa⋅12m32m3=2Pa
Bulk pressure follows modulus times volume-change ratio
Volume change 1 cubic meter over volume 8 cubic meters with modulus 16 Pa gives pressure change 2 Pa.