Probability 30 Correlation 17 Linear programming 17 Derivatives 12 Data analysis 10 Index numbers 10 Sampling 10 Matrices 9 Regression 9 Statistics 9 correlation 9 Linear equations 8 Linear regression 8 Central tendency 6 Quality control 6 Time series 6 probability 6 Geometry 5 Random variables 5 Simplex method 5 index numbers 5 Calculus 4 Determinants 4 Hypothesis testing 4 Tabulation 4 Trigonometry 4 linear regression 4 Data collection 3 Differential Equations 3 Dispersion 3