Two samples comparison
This module is intended for a detailed analysis of two datasets (two samples). The module offers two analyses: independent samples comparison, and paired samples comparison. Independent samples x, y feature no mutual relationship. They can have different sample sizes, in general. Ordering of the elements of both samples is arbitrary and can be changed without any information loss. Main point of this analysis is to decide, whether the expected values E(x) and E(y) of the two samples are different. Weight of peanuts from two different locations can serve as an example of two independent samples. On each location, a few dozens of the peanuts are selected at random and weighted individually.

PDF Two samples comparison - Pdf manual

Example:
Input data:
System A System B
4.18 4.43
4.69 5.42
5.23 4.11
4.72 4.84
4.32 5.52
4.43 6.51
4.91 4.74
4.29 4.32
3.89 4.53
4.91 5.42
5.63 6.67
6.08 7.34
2.41 4.48
Input dialog window:
Two samples comparison
Sample graphical output:
Independent data comparison:
Two samples comparison
Text output:
Compare two samples    
     
Task name : Sheet36  
     
Significance level : 0.05  
Columns to compare : System A System B
     
Sample size : 24 24
Average : 4.477982955 5.078125
Std. deviation : 0.787465729 1.070369937
Variance : 0.620102274 1.145691803
     
Corr. coeff. R(x,y) : 0.225347432  
     
Variance equivalence test    
Variances ratio : 1.84758523  
Degrees of freedom : 23 23
Critical value : 2.014424842  
Conclusion : Variances are EQUIVALENT  
P-value : 0.074221818  
     
Robust variances test    
Variances ratio : 1.84758523  
Corrected degrees of freedom : 10 10
Critical value : 2.978237016  
Conclusion : Variances are EQUIVALENT  
P-value : 0.173707895  
     
Mean equivalence test    
for Equivalent varances    
t-statistic : 2.212532441  
Degrees of freedom : 46  
Critical value : 2.012895599  
Conclusion : Means are DIFFERENT  
P-value : 0.031933164  
     
Mean equivalence test    
for Different variances    
t-statistic : 2.212532441  
Corrected degrees of freedom : 42  
Critical value : 2.018081703  
Conclusion : Means are DIFFERENT  
P-value : 0.032420484  
     
Godness of fit test    
(two-sample Kolmogorov-Smyrnov)    
Difference DF : 0.375  
Critical value : 0.392050138  
Conclusion : Distributions are EQUAL  
Paired data comparison:
Two samples comparison
Paired comparison    
     
Task name : Sheet35  
     
Significance level : 0.05  
Columns to compare : X Y
     
Analysis of difference X - Y    
Sample size : 29  
Average difference : -0.734423981  
Confidence interval: -2.585348422 1.116500459
Std. deviation : 4.865992191  
Variance : 23.67788001  
     
Corr. coeff. R(x,y) : -0.935498387  
     
Test of difference significance  
t-statistic : 3.954994177  
Degrees of freedom : 28  
Critical value : 2.048407142  
Conclusion : Differences are INSIGNIFICANT
P-value : 0.211599993