Tools: stats calculators

Calculating the margin of error of a percent
This is an MS Excel spreadsheet.  Enter the sample size and the percent.  The calculator will automatically calculate the margin of error at the 95% confidence level.  Click here to open in MS Excel

Comparing two ratings to see if they are statistically different
This is an another MS Excel spreadsheet.  Enter the sample size and the percent for the first rating.  Do the same for the second rating.  If the difference in ratings is not statistically significant, the calculator will automatically display 'Not statistically different'.  Otherwise, it will show the confidence level at which the difference is significant (90%, 95% or 99%). Note 1: 95% is a better result than 90%, and 99% is a better result than 95%.  Note 2: 95% or over is commonly accepted as being a significant difference, but 90% is often accepted too.   Click here to open in MS Excel.

If you want to compare ratings for several brands at the same time, there are different options to use, so just let us know and we may be able to do them for you.  Also, we'll be happy to answer any questions you have on using the calculators.