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