Hypothesis Testing

DOE PRACTICAL TEAM MEMBERS (fill this according to your DOE practical):

1. Ryan (Iron Man)

2. Hai Teng (Thor)

3. Fion (Captain America)

4. Isabella (Black Widow)

5. Wayne (Hulk)

Data collected for FULL factorial design using CATAPULT A (fill this according to your DOE practical result):

Thor will use will use Run #2 and Run#4. To determine the effect of projectile weight.

The QUESTION	To determine the effect of Projectile Weight 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 is collected using the factors below: Arm length = 27cm Projectile weight = 0.86 grams and 2.06 grams Stop angle = 55 degree
Step 1: State the statistical Hypotheses:	State the null hypothesis (H0): Using an arm length of 27 cm and a stop angle at 55 degrees, the distance of the flying projectile using 0.86 gram and 2.06 gram projectile weight will be the same. (X1 = X2) State the alternative hypothesis (H1): Using an arm length of 27 cm and a stop angle at 55 degrees, the distance of the flying projectile using 0.86 gram and 2.06 gram projectile weight will be different.  (X1≠ X2)
Step 2: Formulate an analysis plan.	Sample size is 16 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 # 2: Mean (x1):  214.2 Standard deviations (s1): 2.96   State the mean and standard deviation of Run # 4: Mean (x2):  196.1 Standard deviations (s2): 4.73 Compute the value of the test statistic (t):   n1 = 8, n2 = 8   v = 8 + 8 – 2 = 14
Step 4: Make a decision based on result	Type of test (check one only)      1.    Left-tailed test: [__] Critical value tα = - _____      2.    Right-tailed test: [ __]  Critical value tα =  ______      3.    Two-tailed test: [√] Critical value tα/2 = ± 2.145   Use 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 tα = ± 2.145 t = ± 8.58 Therefore, Ho is rejected.
Conclusion that answer the initial question	Since Ho is rejected, H1 is accepted. Hence the projectile weight has significant effect on the flying distance of the projectile.
Compare your conclusion with the conclusion from the other team members.	My other teammate, Ryan, which did the hypothesis testing for runs #1 and #3 and arrived at the same conclusion that the null hypothesis and the alternate hypothesis is accepted. This suggests that projectile weight has a significant impact on the flying distance of the projectile.
What inferences can you make from these comparisons?	From the comparisons, I can infer that there is not any significant interaction between factors A (Arm Length) and B (Projectile Weight) as at both levels of factor A, the flying distance of projectile will still increase when the level of factor B decrease from high to low.
Your learning reflection on this Hypothesis testing activity	At first I did not understand hypothesis testing, but after going through the lesson and doing the practice questions, I understand the that hypothesis testing is use to verify if my hypothesis for experiments to see if a factor has a significant impact on the outcome. This method is a useful tool that I can apply during the final project to find the significance of factor on the outcome.