STATISTICS

Answer the given problem. Analyze what tool should be used.

1. Trees that grow in flood plains are susceptible to overturning. This is typically due to floodwaters exposing the three roots (called soil scouring). Environmental engineers at a certain university investigated the impact of soil scouring on the characteristics of overturned and uprooted trees. Tree pulling experiments were conducted in the floodplains of Komagawa river. Trees were randomly selected to be uprooted in each of three areas that had different scouring conditions.: no scouring (NS), shallow scouring (SS), and deep scouring (DS). During the uprooting of trees, the maximum resistive bending moment at the trunk base (kilonewton-meters) was measured. Simulated data for five medium-sized trees selected at each area are shown in the table. Does soil scouring affect the mean maximum resistive bending moment at the tree trunk base? Use = 0.05 .

None	Shallow	Deep
23.68	11.13	4.27
8.88	29.19	2.36
7.52	13.66	8.48
25.89	20.47	12.09
22.58	23.24	3.46

Follow the steps in solving the problem, namely:

1. Hypothesis ex. H0: = 9.0 H1: 9.0 2. Level of significance ex. = 0.01 3. Test Statistic ex. z = x - 0 / / n 4. Critical Region ex. graph and /2 = +-0.025 5. Computation ex. compute using formula 6. Decision ex. accept H0 since the computed z-value falls in the region of acceptance. 7. Conclusion ex. there is no reason to believe the ...