# Statistic Analysis : T Test

1524 WordsApr 7, 20177 Pages
Statistic Analysis: T-test A t-test is an analysis of two populations means through the use of statistical examination; the two samples are commonly small sample, testing the difference between the samples when the variances of two normal distributions are not known. For instance, in this study, a t-test could be conducted to compare the mean of velocity in grit 80 and that in grit 120 in experiment 1, to see whether there is a significance difference between their means (Starnes, 2010). In the data analysis of this study, GraphPad Software is used to visualize the data. This tool is available at https://www.graphpad.com/quickcalcs/ttest1.cfm. Data will be input to the tool on the website to make a comparison. To do so, select unpaired…show more content…
T Test Results of Experiment 2– Testing Humidity T Test 0g & 5g 0g & 15g 5g & 15g Mean A-B 0.0001723 -0.00128359840 -0.00145588700 P value 0.7710 0.1137 0.0687 95% Confidence Interval (-0.00114712019, 0.00149169739) (-0.00295032588, 0.00038312908) (-0.00305289218, 0.00014111818) Result NOT statistically significant NOT statistically significant Not quite statistically significant Table 10. T Test Results of Experiment 3– Testing Component T Test 200g & 100g 200g & 50g 100g & 50g Mean A-B -0.0004777 -0.0013187 -0.0008410 P value 0.0017 0.0004 0.0064 95% Confidence Interval (-0.00071545658, -0.00023990862) (-0.00183650526, -0.00080088874) (-0.00137064668, -0.00031138212) Result Very statistically significant Extremely statistically significant Very statistically significant Data Visualization In order to make the result of the experiment and the statistics more direct and easier to understand, visualization of data in graphs will be used in this part to help better understand and interpret the trend of the effect of each independent variables on their corresponding dependent variables. Figure 5. Plot of Substrate Granularity vs. Velocity Figure 6. Plot of Substrate Humidity vs. Velocity Figure 7. Plot of Substrate Component vs. Velocity Conclusion & Discussion Overall, this experiment studies the influence of roughness, humidity and components on the behavior of earthworms. To test the impact of these factors, three experiments are