Q: Find the variance and SD of: 2, 4, 6, 8, 10. Mean = 6. Squared deviations: 16, 4, 0, 4, 16. Sum = 40. Variance = 40/5 = 8. SD = sqrt(8) = 2.83. Shortcut check: sum x^2 = 4+16+36+64+100 = 220. 220/5 - 36 = 44 - 36 = 8!