🔍 Key Concepts

• pressure units and how inches of water column relate to psi • the approximate conversion factor between inches of water and pounds per square inch (psi) • using a proportion (ratio) to scale a known conversion up to 8 inches of water

💭 Think About

• First, recall or look up how many inches of water are equal to 1 psi, then think about whether 8 inches of water should be less than or greater than 1 psi. • Set up a simple ratio: if 1 psi equals a certain number of inches of water, what fraction of 1 psi is 8 inches? • Estimate the answer’s order of magnitude: should 8 inches of water be closer to 0.1 psi, 0.3 psi, 0.7 psi, or more than 1 psi?

✅ Before You Answer

• Verify the standard engineering conversion between inches of water column and psi before doing any math. • Check that your final value in psi is less than 1 psi, since 8 inches of water is a relatively small pressure difference. • Confirm that your arithmetic (multiplication or division) keeps the units consistent and that you didn’t invert the conversion ratio.