HYPOTHESIS TESTING

 

The QUESTION	To determine the effect of stop angle on the flying distance of the projectile
Scope of the test	The human factor is assumed to be negligible. Therefore different user will not have any effect on the flying distance of projectile.   Flying distance for catapult A is collected using the factors below: Arm length =  28cm Projectile weight = 2.01 grams Stop angle = 60 degree and 90 degree
Step 1: State the statistical Hypotheses:	State the null hypothesis (H0): Ho : X1= X2     State the alternative hypothesis (H1): H1: X1≠ X2
Step 2: Formulate an analysis plan.	Sample size is 8. Therefore t-test will be used.     Since the sign of H1 is ≠, a two tailed test is used.     Significance level (α) used in this test is 0.05
Step 3: Calculate the test statistic	State the mean and standard deviation of Run #4: X1=161.1, s1=3.72   State the mean and standard deviation of Run #8: X2=101.7, s2=1.03       Compute the value of the test statistic (t): σ=2.91785 v=14 t=40.714
Step 4: Make a decision based on result	Type of test (check one only) Two-tailed test:  Critical value tα/2 = ± 2.145   Using the t-distribution table to determine the critical value of tα or tα/2 Compare the values of test statistics, t, and critical value(s), tα or ± tα/2   Therefore Ho is rejected.
Conclusion that answer the initial question	Based on t-distribution table, critical value for t distribution of 95% and v=14 =2.154. t is outside of t distribution curve, therefore stop angle has an effect on flying distance of projectile.
Compare your conclusion with the conclusion from the other team members.	Factor A: Ho is rejected, arm length has an effect flying distance of projectile. Factor B: Ho is rejected, projectile weight has no effect on flying distance of projectile.
What inferences can you make from these comparisons?	All factors A and C has an effect on flying distance of projectile while factor B has no effect on flying distance of projectile.
Your learning reflection on this Hypothesis testing activity	It feels like another way to find effects of factor instead of DOE. It allow us to also know whether things are in working conditions or not which could come in handy when we use it to find results. Overall, it was a insightful activity and I learned and gained much.