Environmental Education

Comparison
of Two Proportions

by Sultan

Z test comparison of two proportions:

To compare two proportions the best software you can
use is MedCalc. It easily 



calculates from inputting only four Numbers.First calculate
percentage for your data.



Then run Medcalc software.

From Menu Select:



Test

·                     Comparison of two Proportions

In the box enter data for the 1st set.   Data in percentage:   Proportions %:  _79

Enter the Number of cases (pop) for the 1st set
of Data: Number of cases:_120

      Enter the Data for the second using same Method 

      In the box enter data for the 2nd set. Data in percentage: Proportions %:     _65



      Enter the Number of cases (pop) for the 2nd set
of data: Number of cases:_135

Press the Test button.

It
will look like this

If the result is less than 0.05 then there is
significant difference in the two 



proportions. In this case the P value is
0.0195 which is less than 0.05 



which mean that there is significant difference in
both proportions.The



difference for this proportion is 14.0% and 95%
confidence interval for



this difference.

Download free trail  Software from:   http://www.medcalc.org