Normal distribution Probability 6 Statistics 6 Correlation 3 Frequency distribution 3 Central tendency 2 Regression 2 distribution - 2 distribution - t 2 Biology 1 Geometric Mean 1 Poisson distribution 1 Psychomestrics 1 Random variables 1 Sampling 1 Stratified sampling 1 Surveys 1 Variability 1 Variance 1 Variation 1