1

Apriori Sample Size Calculator for Multiple Regression


This calculator will tell you the minimum required sample size for a multiple regression study, given the desired probability level, the number of predictors in the model, the anticipated effect size, and the desired statistical power level.


2

Adjusted Rsquare Calculator (Population Rsquare)


This calculator will compute an adjusted R^{2} value (i.e., the population squared multiple correlation), given an observed (sample) R^{2}, the number of predictors in the model, and the total sample size.




5

Critical Fvalue Calculator


This calculator will tell you the critical value of the Fdistribution, given the probability level, the numerator degrees of freedom, and the denominator degrees of freedom.



7

fsquare Effect Size Confidence Interval Calculator


This calculator will compute the 99%, 95%, and 90% confidence intervals for the f^{2} effect size associated with a multiple regression study, given the f^{2} value, the number of predictors in the model, and the total sample size.


8

FValue and pValue Calculator for Multiple Regression


This calculator will tell you the Fisher Fvalue for a multiple regression study and its associated probability level (pvalue), given the model R^{2}, the number of predictors in the model, and the total sample size.




11

Rsquare Confidence Interval Calculator


This calculator will compute the 99%, 95%, and 90% confidence intervals for an R^{2} value (i.e., a squared multiple correlation), given the value of the Rsquare, the number of predictors in the model, and the total sample size.


12

Regression Coefficient Confidence Interval Calculator


This calculator will compute the 99%, 95%, and 90% confidence intervals for a regression coefficient, given the value of the regression coefficient, the standard error of the regression coefficient, the number of predictors in the model, and the total sample size.


13

Regression Intercept Confidence Interval Calculator


This calculator will compute the 99%, 95%, and 90% confidence intervals for a regression intercept (i.e., the regression constant), given the value of the regression intercept, the standard error of the regression intercept, the number of predictors in the model, and the total sample size.


14

Significance of the Difference between Two Slopes Calculator


This calculator will determine whether the slopes of two lines are significantly different from each other, given the slope, standard error, and sample size for each line. Values returned from the calculator include the probability value, the tvalue for the significance test, and the degrees of freedom. A probability value of less than 0.05 indicates that the two slopes are significantly different from each other.


