Number Explorer
What is the 10th Fibonacci number?
✓ 55 (1,1,2,3,5,8,13,21,34,55)
Geometry
A triangle has angles 90° and 45°. What is the third angle?
✓ 45° — angles of a triangle sum to 180°
Statistics
If the mean of 5 numbers is 12, what is their sum?
✓ 60 (sum = mean × count = 12 × 5)
Z-Table
What is the z-score for a value exactly 2 standard deviations above the mean?
✓ z = 2.00 → Φ(2.00) ≈ 0.9772 (97.72th percentile)
