If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains ***.kastatic.org** and ***.kasandbox.org** are unblocked.

Main content

AP.STATS: UNC‑1 (EU), UNC‑1.I (LO), UNC‑1.I.5 (EK) CCSS.Math: HSS.ID.A.4, HSS.ID.A