Normal Probability Workflow
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Draw and shade. State X~N(mu,sigma). Standardize z=(x-mu)/sigma or use pnorm. For intervals subtract CDFs. For right tails use lower.tail=FALSE. Verify the area is between zero and one and write one sentence with units.

Original synthetic data generated for STATLAB Academy. No textbook data used.
Educational material for STATLAB Academy. Verify assumptions, units, tail direction, and rounding before making a decision.