Alphabetical Statistical Symbols Symbol Text Equivalent Meaning Formula Link to Glossary (if appropriate) a Y- intercept of least square regression line , for line Regression: y on x b Slope of least squares regression line for line Regression: y on x Binomial distribution with parameters n and p Discrete probability distribution for the probability of number of successes in n independent random trials under the identical conditions. If X follows then, , Where, , r = 0,1,2, …….,n, Binomial Distribution c Confidence level Confidence interval nCr n-c-r Combinations (number of combinations of n objects taken r at a time) , where n-c-r Combinations (number of combinations of n objects taken r at a time) , where Covariance between X and Y Covariance between X & Y CV Coefficient of variation df Degree(s) of freedom E Maximal error tolerance for large samples E (f(x)) Expected value of f(x) f Frequency number of times score. F F-distribution variable where n1 and n2 are the corresponding degrees of freedom. F-distribution, Hypothesis testing for equality of 2 variances. or Distribution function . f(x) or Probability mass function Depends on the distribution. H0 H-naught Null hypothesis The null hypothesis is the hypothesis about the population parameter. Testing of hypothesis H1 H-one Alternate hypothesis An alternate hypothesis is constructed in such a way that it is the one to be accepted when the null hypothesis must be rejected. Testing of hypothesis IQR Interquartile range Measures of central tendency. MS M-S Mean square Analysis of variance (ANOVA) n Sample size. number of units in a sample. N Population size Number of units in the population. n-p-r Permutation (number of ways to arrange in order n distinct objects taking them r at a time) where n-p-r Permutation (number of ways to arrange in order n distinct objects taking them r at a time) , where p-hat Sample proportion Binomial distribution Probability of A given B Conditional probability Probability of x Probability of x p-value The attained level of significance. P value is the smallest level of significance for which the observed sample statistic tells us to reject the null hypothesis. Q Probability of not happening of the event Q1 Q-one First quartile Median of the lower half of the data that is data below median. Measures of central tendency Q2 Q-two Second quartile Or Median Central value of an ordered data. Measures of central tendency Q3 Q-three Third quartile Median of the upper half of the data that is data above the median. Measures of central tendency R Sample Correlation coefficient r2 r-square Coefficient of determination R2 r-square Multiple correlation coefficient S Sample standard deviation for ungrouped data. for grouped data. Measures of dispersion S2 S-square Sample variance for ungrouped data. for grouped data. Measures of dispersion s-e- square Error variance SD Sample Standard deviation for ungrouped data. for grouped data. Bowley’s coefficient of skewness Measures of skew ness Pearson’s coefficient of skewness Measures of skew ness Sum of squares for ungrouped data for grouped data t Student’s t variable t-distribution tc t critical The critical value for a confidence level c. Number such that the area under the t distribution for a given number of degrees of freedom falling between and is equal to c. Testing of hypothesis Var(X) Variance of X Variance of X X Independent variable or explanatory variable in regression analysis Eg. In the study of, yield obtained & the irrigation level, independent variable is, Irrigation level. x-bar Arithmetic mean or Average of X scores. for ungrouped data. for grouped data Measures of central tendency y Dependent variable or response variable in regression analysis Eg. In the study of, yield obtained & the irrigation level, dependent variable is, Yield obtained. Z Z-score Standard normal variable (Normal variable with mean = 0 & SD = 1) , where X follows Normal . Standard normal distribution z critical The critical value for a confidence level c. Number such that the area under the standard normal curve falling between and is equal to c. Testing of hypothesis Confidence interval
Posted on: Sun, 23 Mar 2014 12:40:59 +0000