PRACTICE ASSESSMENT 2026 CERTIFICATION
EVALUATION EXPERT CHECKED
◉ Critical value (z alpha/2). Answer: the z-score cutting off alpha/2
in each tail of the normal curve (for 95%, alpha = 0.05 so z0.025 =
1.96)
◉ Interpretation of CI. Answer: We are __% confident that the
interval contains the true population mean mu
◉ ZInterval (calculator). Answer: STAT → TESTS → 7:ZInterval →
Stats → enter sigma, x-bar, n, C-Level → Calculate
◉ TInterval (calculator). Answer: STAT → TESTS → 8:TInterval →
Stats → enter s, x-bar, n, C-Level → Calculate
◉ 1-PropZInt (calculator). Answer: STAT → TESTS → A:1-PropZInt →
enter x, n, C-Level → Calculate
◉ Use 1-PropZInt. Answer: when data are categorical (count of
successes out of n trials)