Probability Statistics 86 Mathematics 28 Correlation 25 Sampling 21 Regression 18 Random variables 12 Hypothesis testing 7 Variation 7 Mathematical statistics 6 Normal distribution 6 Variance 6 Dispersion 5 Index numbers 5 Linear programming 5 Regression analysis 5 Time series 5 set theory 5 Algebra 4 Biometry 4 Biostatistics 4 Frequency Distribution 4 Genetics 4 Linear regression 4 Central tendency 3 Chromosome 3 Economics 3 Hypotheses 3 Matrices 3 Medical statistics 3