Quick Z-Score Lookup
P(Z ≤ z) =
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Click any cell to highlight and copy the value. Table shows P(Z ≤ z) cumulative probabilities.
Understanding the Z-Table
What Does P(Z ≤ z) Mean?
The Z-table shows the area (probability) to the left of a Z-score. For example, P(Z ≤ 1.00) = 0.8413, meaning 84.13% of values fall below Z = 1.
Finding Right-Tail Probability
For P(Z ≥ z), use: 1 − P(Z ≤ z). For example, P(Z ≥ 1.96) = 1 − 0.9750 = 0.0250, meaning 2.5% of values lie above Z = 1.96.
Finding Area Between Two Values
For P(z₁ ≤ Z ≤ z₂), compute: P(Z ≤ z₂) − P(Z ≤ z₁). For 95% CI: P(−1.96 ≤ Z ≤ 1.96) = 0.975 − 0.025 = 0.950.