Monday, November 19, 2012

Comparison of two proportions



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