15. In tree crop spraying, an airblast sprayer was used with and without an air oscil- lator on grapefruit and orange trees in an experiment to evaluate the delivery of a solution. Data for the four treatments (grapefruit trees with oscillator, grape- fruit trees without oscillator, orange trees with oscillator, orange trees without oscillator) consisted of 72 observations. The corresponding sample means and sample standard deviations of the solution deposited in nanograms per square centimeter (ng/cmz) appear in Table 2.9. (a) Analyze the data as a one-way layout by constructing the corresponding ANOVA table. Are there signicant differences between the treatments? (Him: The mean squared error can be calculated by pooling the sample variances and the treatment sum of squares can be determined from the sample means.) *(h) The analysis in (a) assumes the error variance does not depend on the particular treatment. Are the data consistent with this assumption? Table 2.9 Summary Data, Airsprayer Experiment Treatment Mean Standard Deviation Grapefruit Trees with Oscillator 514 330 Orange Trees with Oscillator 430 360 Grapefruit Trees withoul Oscillator 590 460 Orange Trees without Oscillator 450 325