Question

Do different treatments affect the weights of poplar trees? Data below report weights (in kilograms) of randomly selected poplar trees given different treatments (none, fertilizer, irrigation, fertilizer + irrigation). The treatments are assigned at random to the trees. Conduct a complete hypothesis testing to investigate if there are significant differences in the mean weight of poplar trees at α= 0.05 None (N) Fertilizer (F) Irrigation (I) Fertilizer + Irrigation

none 0.18 0.78 0.23 2.03 0.02

Fertilizer 0.54 0.40 2.07 0.16 0.42,

irrigation 0.34 1.92 0.07 0.88 0.16,

fertilizer + irrigation- 1.87 0.28 0.64

Complete the ANOVA using p value and f value methods

Answer 1

Using Minitab software, (Stat -> ANOVA -> One way), we get the following output :

The value of F statistic = 0.09

P-value = 0.965

Since P-value > 0.05, so we fail to reject H₀ at 0.05 level of significance and we can conclude that there are no significant differences in the mean weight of poplar trees.