In: Statistics and Probability
| 
 Knee Diameter (cm)  | 
||
| 
 Contralateral Control  | 
 OA Knee  | 
|
| 
 Patient 1  | 
 16  | 
 18  | 
| 
 Patient 2  | 
 24  | 
 28  | 
| 
 Patient 3  | 
 22  | 
 25  | 
| 
 Patient 4  | 
 10  | 
 12  | 
| 
 Patient 5  | 
 24  | 
 27  | 
| 
 Patient 6  | 
 17  | 
 19  | 
Let difference, d=OA Knee - Contralateral Control
The hypotheses are:

Enter data in excel.
Click on Data->Data Analysis.
Click on t-Test: Paired Two Sample for Means.
Enter both data ranges and click ok.
The output is shown below:

Since p-value = 0.000 is extremely small, reject the null hypothesis. With 95% confidence, we can conclude that osteoarthritis increases joint swelling in OA knees in comparison to their contralateral control knee.