25. HHyyppootthheessiiss TTeessttiinngg
Two-sample T for Time/Inspection vs Time/Inspection(New)
N Mean StDev SE Mean
Time/Insp 31 20.26 7.00 1.3
Time/Inspection(New) 53 21.13 6.43 0.88
Difference = mu (Time/Insp) - mu (Time/Inspection(New))
Estimate for difference: -0.87
95% CI for difference: (-3.95, 2.20)
T-Test of difference = 0 (vs not =): T-Value = -0.57 P-Value = 0.572 DF = 58
Conclusion:
Demonstrating T-test, could not give us enough evidence to reject the null
hypothesis, so we can not say that base on this # the process has improved;
Specially since the confidence interval covers 0 value.
26. HHyyppootthheessiiss TTeessttiinngg
Two-Sample T-Test and CI: No. Insp, No. Inspection(New)
N Mean StDev SE Mean
No. Insp 31 37.48 7.99 1.4
No. Inspection(New) 53 65.5 23.1 3.2
Difference = mu (No. Insp) - mu (No. Inspection(New))
Estimate for difference: -27.97
95% CI for difference: (-34.90, -21.04)
T-Test of difference = 0 (vs not =): T-Value = -8.05 P-Value = 0.000 DF = 70
Conclusion:
This T-Test actually confirms that the change we have made to the process
has improved the outcome of the system which means number of inspection
per day has increased .