25 Statistical Symbols to Know on Sight 1. Degrees of freedom 2. Less than or equal to 3. Greater than or equal to 4. Not equal 5. Omega squared 6. Sample variance 7. Beta 8. Alternative hypothesis 9. Chi squared 10. Square root 11. Population mean 12. Sample correlation 13. Population standard deviation 14. Sigma (sum of) 15. Population variance 16. Sample mean 17. Alpha level 18. Greater than 19. Sample standard deviation 20. Null hypothesis 21. Infinity 22. Coefficient of determination 23. Less than 24. Equal to 25. Mutually exclusive events © 2015 American College of Education df ≤ ≥ ≠ Ω2 σ2 or s2 � β Ha χ2 √ μ r σ or S Σ σ2 or S2 � X α > � or s σ H0 ∞ R2 < = 00 1