Basic Statistical Testing

To understand the results of any survey, two calculations are necessary: the margin of error and the statistical significance of any differences found. Click here for a basic explanation of the relevant statistic procedures. To conduct the calculations yourself, or to view the actual formulas, click on the appropriate link in the box to the right.

 

Basic Statistical Testing Options

Calculate the margin of error for ...

Proportions/Percentages Means

Test whether a difference is significant between two ...

Proportions/Percentages Means

Other analyses...

Chi-Square Calculation Formula

Basic Statistical Testing for Significant
Difference Between Two Proportions/Percentages

Step 1:
desired confidence level: 99%   95%   90%

Step 2:
proportion 1:  %
proportion 2: %

Step 3:
sample size 1: 
sample size 2:
   <- check this box when group 2 is actually part of the larger sample

Step 4:
population size: infinite   actual/estimated
  • use 'infinite' when the group is larger than 1, or you don't know the actual size of the overall population


  

z =


See Formula